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

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

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

@@ -2,6 +2,8 @@
 # shellcheck disable=SC2086 # we want word splitting
 set -uex
 
+uncollapsed_section_start piglit "Building piglit"
+
 # When changing this file, you need to bump the following
 # .gitlab-ci/image-tags.yml tags:
 # DEBIAN_TEST_GL_TAG
@@ -32,3 +34,5 @@ if [ "${PIGLIT_BUILD_TARGETS:-}" = "piglit_replayer" ]; then
          -exec rm -rf {} \; 2>/dev/null
 fi
 popd
+
+section_end piglit

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

@@ -84,8 +84,6 @@ apt-get install -y --no-remove "${DEPS[@]}" "${EPHEMERAL[@]}" \
 
 ############### Build piglit
 
-uncollapsed_section_switch piglit "Building Piglit"
-
 PIGLIT_OPTS="-DPIGLIT_USE_WAFFLE=ON
 	     -DPIGLIT_USE_GBM=ON
 	     -DPIGLIT_USE_WAYLAND=ON

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

@@ -82,8 +82,6 @@ apt-get install -y --no-remove --no-install-recommends \
 
 ############### Build piglit replayer
 
-uncollapsed_section_switch piglit "Building Piglit for Vulkan (traces only)"
-
 # We don't run any _piglit_ Vulkan tests in the containers.
 PIGLIT_OPTS="-DPIGLIT_USE_WAFFLE=ON
 	     -DPIGLIT_USE_GBM=OFF