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

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

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

@@ -9,6 +9,8 @@
 
 set -uex
 
+uncollapsed_section_start apitrace "Building apitrace"
+
 APITRACE_VERSION="0a6506433e1f9f7b69757b4e5730326970c4321a"
 
 git clone https://github.com/apitrace/apitrace.git --single-branch --no-checkout /apitrace
@@ -23,3 +25,5 @@ cp _build/eglretrace build
 ${STRIP_CMD:-strip} build/*
 find . -not -path './build' -not -path './build/*' -delete
 popd
+
+section_end apitrace