Merge branch 'ab/cc-package-fixes' into maint

Correct choices of C compilers used in various CI jobs.
source: <patch-v3-1.1-8b3444ecc87-20220422T092015Z-avarab@gmail.com>

* ab/cc-package-fixes:
  CI: select CC based on CC_PACKAGE (again)

ci/lib.sh

@@ -122,7 +122,7 @@ then
 	test macos != "$CI_OS_NAME" || CI_OS_NAME=osx
 	CI_REPO_SLUG="$GITHUB_REPOSITORY"
 	CI_JOB_ID="$GITHUB_RUN_ID"
-	CC="${CC:-gcc}"
+	CC="${CC_PACKAGE:-${CC:-gcc}}"
 	DONT_SKIP_TAGS=t
 
 	cache_dir="$HOME/none"