build: skip cache when no version is pinned

Co-Authored-By: Claude <svc-devxp-claude@slack-corp.com>

Author: zimeg

cli/action.yml

@@ -35,7 +35,7 @@ runs:
         fi
 
     - name: Cache Slack CLI
-      if: steps.slack-cli-check.outputs.exists != 'true'
+      if: steps.slack-cli-check.outputs.exists != 'true' && inputs.version != ''
       id: cache-cli
       uses: actions/cache@0400d5f644dc74513175e3cd8d07132dd4860809 # v4.2.4
       with: