ci: make shellcheck happy about .gitlab-ci/container/ directory

Makes easier do changes, when shellcheck is warning-free.

Reviewed-by: Guilherme Gallo <guilherme.gallo@collabora.com>
Signed-off-by: David Heidelberg <david.heidelberg@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/17574>

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

@@ -1,4 +1,5 @@
 #!/bin/bash
+# shellcheck disable=SC2086 # we want word splitting
 
 set -ex
 
@@ -8,9 +9,11 @@ git checkout b2c9d8f56b45d79f804f4cb5ac62520f0edd8988
 patch -p1 <$OLDPWD/.gitlab-ci/piglit/disable-vs_in.diff
 cmake -S . -B . -G Ninja -DCMAKE_BUILD_TYPE=Release $PIGLIT_OPTS $EXTRA_CMAKE_ARGS
 ninja $PIGLIT_BUILD_TARGETS
+# shellcheck disable=SC2038,SC2185 # TODO: rewrite find
 find -name .git -o -name '*ninja*' -o -iname '*cmake*' -o -name '*.[chao]' | xargs rm -rf
 rm -rf target_api
-if [ "x$PIGLIT_BUILD_TARGETS" = "xpiglit_replayer" ]; then
+if [ "$PIGLIT_BUILD_TARGETS" = "piglit_replayer" ]; then
+    # shellcheck disable=SC2038,SC2185 # TODO: rewrite find
     find ! -regex "^\.$" \
          ! -regex "^\.\/piglit.*" \
          ! -regex "^\.\/framework.*" \