Check old license format in crate submissions (#508)

* gh-build-crate.sh: check index in strict mode

* Add specific check for "Warning:" during index load

Co-authored-by: GHA <actions@github.com>

scripts/gh-build-crate.sh

@@ -34,6 +34,15 @@ alr index --del community || true
 # Show environment for the record
 env
 
+# Check index for obsolescent features
+echo STRICT MODE index checks
+alr index --check
+
+# Check no warning during index loading.
+# Such a warning would also happen during `alr printenv`, breaking it.
+# TODO: remove after old license deprecation.
+alr search --crates 2>&1 | grep "Warning:" && exit 1
+
 # Test crate
 for file in $CHANGES; do