CP-311259: Use local opam pin until feature merge

Signed-off-by: Lin Liu <lin.liu01@citrix.com>

Author: Lin Liu

.github/workflows/setup-xapi-environment/action.yml

@@ -59,7 +59,8 @@ runs:
         opam-repositories: |
           xs-opam: ${{ steps.dotenv.outputs.repository }}
         dune-cache: true
-        opam-pin: false
+        opam-pin: true
+        pin: .
         cache-prefix: v3-${{ steps.system-info.outputs.name }}-${{ steps.system-info.outputs.release }}
       env:
         DUNE_CACHE_STORAGE_MODE: copy