ci/container: move mold build section into the script itself

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

.gitlab-ci/container/build-mold.sh

@@ -10,6 +10,8 @@ set -ex
 # FEDORA_X86_64_BUILD_TAG
 # KERNEL_ROOTFS_TAG
 
+uncollapsed_section_start mold "Building mold"
+
 MOLD_VERSION="2.32.0"
 
 git clone -b v"$MOLD_VERSION" --single-branch --depth 1 https://github.com/rui314/mold.git
@@ -26,3 +28,5 @@ find /usr/bin \( -name '*-ld' -o -name 'ld' \) \
 
 popd
 rm -rf mold
+
+section_end mold

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

@@ -137,8 +137,6 @@ fi
 
 ############### Build mold
 
-uncollapsed_section_switch mold "Building mold linker"
-
 . .gitlab-ci/container/build-mold.sh
 
 ############### Build LLVM-SPIRV translator