ci/container: move vulkan-validation build section into the script itself

Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/32241>

.gitlab-ci/container/build-vulkan-validation.sh

@@ -7,6 +7,8 @@
 
 set -uex
 
+uncollapsed_section_start vulkan-validation "Building Vulkan validation layers"
+
 VALIDATION_TAG="snapshot-2024wk39"
 
 git clone -b "$VALIDATION_TAG" --single-branch --depth 1 https://github.com/KhronosGroup/Vulkan-ValidationLayers.git
@@ -17,3 +19,5 @@ ninja -C build
 cmake --install build --strip
 popd
 rm -rf Vulkan-ValidationLayers
+
+section_end vulkan-validation

.gitlab-ci/container/debian/test-gl.sh

@@ -116,8 +116,6 @@ DEQP_TARGET=surfaceless \
 
 ############### Build validation layer for zink
 
-uncollapsed_section_switch vvl "Building Vulkan validation layers"
-
 . .gitlab-ci/container/build-vulkan-validation.sh
 
 ############### Build nine tests