gitlab-ci: make needs explicitly empty where possible

In a pipeline with the `prep` stage, all `build` stage jobs without
an explicit `needs` list implicitly `needs` all `prep` job
artifacts. Make these explicitly empty so that the jobs can start
without waiting for and downloading the `prep` artifacts which are
then ignored anyways.

.gitlab-ci.yml

@@ -91,6 +91,7 @@ b:version-update:
     variables:
         CMAKE_CI_JOB_UPDATES_VERSION: "true"
         CMAKE_CI_JOB_NO_MR: "true"
+    needs: []
 
 # Documentation builds
 
@@ -120,6 +121,7 @@ l:spellcheck:
         - .cmake_spellcheck_linux
         - .linux_x86_64_tags
         - .rules
+    needs: []
 
 l:iwyu-debian13:
     extends:
@@ -128,6 +130,7 @@ l:iwyu-debian13:
         - .linux_x86_64_tags
         - .cmake_cdash_artifacts
         - .rules
+    needs: []
 
 l:tidy-fedora44:
     extends:
@@ -137,6 +140,7 @@ l:tidy-fedora44:
         - .linux_x86_64_tags
         - .cmake_cdash_artifacts
         - .rules
+    needs: []
 
 l:pvs-studio-fedora44:
     extends:
@@ -149,6 +153,7 @@ l:pvs-studio-fedora44:
         CMAKE_CI_JOB_CONTINUOUS: "true"
         CMAKE_CI_JOB_NIGHTLY: "true"
         CMAKE_CI_JOB_NO_MR: "true"
+    needs: []
 
 l:sphinx-fedora44:
     extends:
@@ -160,6 +165,7 @@ l:sphinx-fedora44:
     variables:
         CMAKE_CI_JOB_CONTINUOUS: "true"
         CMAKE_CI_JOB_HELP: "true"
+    needs: []
 
 l:clang-analyzer-fedora44:
     extends:
@@ -169,6 +175,7 @@ l:clang-analyzer-fedora44:
         - .rules
     variables:
         CMAKE_CI_JOB_NIGHTLY: "true"
+    needs: []
 
 l:clang-fuzzing-fedora44:
     extends:
@@ -176,6 +183,7 @@ l:clang-fuzzing-fedora44:
         - .cmake_build_linux
         - .linux_x86_64_tags
         - .rules
+    needs: []
 
 l:clazy-fedora44:
     extends:
@@ -183,6 +191,7 @@ l:clazy-fedora44:
         - .cmake_build_linux
         - .linux_x86_64_tags
         - .rules
+    needs: []
 
 # Coverage builds
 
@@ -196,6 +205,7 @@ b:fedora44-gcc-gcov:
     variables:
         CMAKE_CI_JOB_NIGHTLY: "true"
         CMAKE_CI_JOB_RUN_MANUALLY: "true"
+    needs: []
 
 t:fedora44-gcc-gcov:
     extends:
@@ -234,6 +244,7 @@ b:fedora44-bullseye-coverage:
         CMAKE_CI_JOB_NIGHTLY: "true"
         CMAKE_CI_JOB_NO_MR: "true"
         CMAKE_CI_JOB_RUN_MANUALLY: "true"
+    needs: []
 
 t:fedora44-bullseye-coverage:
     extends:
@@ -275,6 +286,7 @@ b:centos7-x86_64:
     variables:
         CMAKE_CI_ARTIFACTS_NAME: "artifacts-centos7-x86_64"
         CMAKE_CI_JOB_RUN_MANUALLY: "true"
+    needs: []
 
 b:centos8-aarch64:
     extends:
@@ -287,6 +299,7 @@ b:centos8-aarch64:
         CMAKE_CI_ARTIFACTS_NAME: "artifacts-centos8-aarch64"
         CMAKE_CI_JOB_NO_MR: "true"
         CMAKE_CI_JOB_RUN_MANUALLY: "true"
+    needs: []
 
 t:debian13-ninja:
     extends:
@@ -691,6 +704,7 @@ b:fedora44-ninja:
     variables:
         CMAKE_CI_JOB_CONTINUOUS: "true"
         CMAKE_CI_JOB_RUN_MANUALLY: "true"
+    needs: []
 
 b:fedora44-makefiles-symlinked:
     extends:
@@ -702,6 +716,7 @@ b:fedora44-makefiles-symlinked:
     variables:
         CMAKE_CI_JOB_NIGHTLY: "true"
         CMAKE_CI_JOB_RUN_MANUALLY: "true"
+    needs: []
 
 b:debian13-makefiles-inplace:
     extends:
@@ -712,6 +727,7 @@ b:debian13-makefiles-inplace:
     variables:
         CMAKE_CI_JOB_NIGHTLY: "true"
         CMAKE_CI_JOB_RUN_MANUALLY: "true"
+    needs: []
 
 b:debian13-extdeps:
     extends:
@@ -722,6 +738,7 @@ b:debian13-extdeps:
     variables:
         CMAKE_CI_JOB_NIGHTLY: "true"
         CMAKE_CI_JOB_RUN_MANUALLY: "true"
+    needs: []
 
 b:debian13-aarch64-extdeps:
     extends:
@@ -732,6 +749,7 @@ b:debian13-aarch64-extdeps:
     variables:
         CMAKE_CI_JOB_NIGHTLY: "true"
         CMAKE_CI_JOB_RUN_MANUALLY: "true"
+    needs: []
 
 b:fedora44-extdeps:
     extends:
@@ -742,6 +760,7 @@ b:fedora44-extdeps:
     variables:
         CMAKE_CI_JOB_NIGHTLY: "true"
         CMAKE_CI_JOB_RUN_MANUALLY: "true"
+    needs: []
 
 t:fedora44-ninja:
     extends:
@@ -966,6 +985,7 @@ b:fedora44-asan:
     variables:
         CMAKE_CI_JOB_NIGHTLY: "true"
         CMAKE_CI_JOB_RUN_MANUALLY: "true"
+    needs: []
 
 t:fedora44-asan:
     extends:
@@ -1004,6 +1024,7 @@ b:macos-x86_64-ninja:
     variables:
         CMAKE_CI_JOB_NO_MR: "true"
         CMAKE_CI_JOB_RUN_MANUALLY: "true"
+    needs: []
 
 b:macos-arm64-ninja:
     extends:
@@ -1015,6 +1036,7 @@ b:macos-arm64-ninja:
     variables:
         CMAKE_CI_JOB_CONTINUOUS: "true"
         CMAKE_CI_JOB_RUN_MANUALLY: "true"
+    needs: []
 
 b:macos-arm64-ninja-symlinked:
     extends:
@@ -1026,6 +1048,7 @@ b:macos-arm64-ninja-symlinked:
     variables:
         CMAKE_CI_JOB_NIGHTLY: "true"
         CMAKE_CI_JOB_RUN_MANUALLY: "true"
+    needs: []
 
 b:macos-arm64-pch:
     extends:
@@ -1036,6 +1059,7 @@ b:macos-arm64-pch:
     variables:
         CMAKE_CI_JOB_NIGHTLY: "true"
         CMAKE_CI_JOB_RUN_MANUALLY: "true"
+    needs: []
 
 t:macos-x86_64-ninja:
     extends:
@@ -1084,6 +1108,7 @@ b:macos-x86_64-makefiles:
         - .rules
     variables:
         CMAKE_CI_JOB_RUN_MANUALLY: "true"
+    needs: []
 
 t:macos-x86_64-makefiles:
     extends:
@@ -1258,6 +1283,7 @@ b:windows-vs2026-x64-ninja:
     variables:
         CMAKE_CI_JOB_CONTINUOUS: "true"
         CMAKE_CI_JOB_RUN_MANUALLY: "true"
+    needs: []
 
 b:windows-vs2026-x64-pch:
     extends:
@@ -1268,6 +1294,7 @@ b:windows-vs2026-x64-pch:
     variables:
         CMAKE_CI_JOB_NIGHTLY: "true"
         CMAKE_CI_JOB_RUN_MANUALLY: "true"
+    needs: []
 
 t:windows-vs2026-x64-ninja:
     extends:
@@ -1621,6 +1648,7 @@ b:windows-arm64-vs2026-ninja:
     variables:
         CMAKE_CI_JOB_NIGHTLY: "true"
         CMAKE_CI_JOB_RUN_MANUALLY: "true"
+    needs: []
 
 t:windows-arm64-vs2026-ninja:
     extends: