ci: pin cross to a commit before they bumped msrv (#9712)

* ci: pin `cross` to a commit before they bumped msrv

bump commit: cross-rs/cross@7129d5a
pre-bump commit: cross-rs/cross@1b8cf50

* Update test-core.yml

.github/workflows/test-core.yml

@@ -93,8 +93,9 @@ jobs:
 
       - name: test (using cross)
         if: ${{ matrix.platform.cross }}
+        # update or remove the rev once we update the MSRV from 1.70.0
         run: |
-          cargo install cross --git https://github.com/cross-rs/cross --locked
+          cargo install cross --git https://github.com/cross-rs/cross --rev 20c73df79c9aaf78a2ad2e9fe8ae981668a729dc --locked
           cross ${{ matrix.platform.command }} --target ${{ matrix.platform.target }} ${{ matrix.features.args }}
 
       - name: test (using cargo)