fix(ci): use python to determine if it's a tag

terraform/pipeline/tag.py

@@ -4,7 +4,9 @@
 REASON = os.environ["REASON"]
 # use variable corresponding to tag triggers
 SOURCE = os.environ["INDIVIDUAL_SOURCE"]
-IS_TAG = os.environ["IS_TAG"].lower() == "true"
+
+SOURCE_BRANCH = os.environ["SOURCE_BRANCH"]
+IS_TAG = SOURCE_BRANCH.startswith("refs/tags/") is True
 
 if REASON == "IndividualCI" and IS_TAG:
     if re.fullmatch(r"20\d\d.\d\d.\d+-rc\d+", SOURCE):