[KYUUBI #1901] [GA] Fix checkout version

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### _Why are the changes needed?_
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Fix the version of `actions/checkout` in file .github/workflows/publish-snapshot.yml.

```
Error: Unable to resolve action `actions/checkout2.3.5`, unable to find version `2.3.5`
```

see https://github.com/apache/incubator-kyuubi/runs/5177066290?check_suite_focus=true for details.

### _How was this patch tested?_
- [ ] Add some test cases that check the changes thoroughly including negative and positive cases if possible

- [ ] Add screenshots for manual tests if appropriate

- [ ] [Run test](https://kyuubi.apache.org/docs/latest/develop_tools/testing.html#running-tests) locally before make a pull request

Closes #1901 from cfmcgrady/ga.

Closes #1901

276380c [Fu Chen] fix checkout version

Authored-by: Fu Chen <cfmcgrady@gmail.com>
Signed-off-by: Cheng Pan <chengpan@apache.org>

Author: cfmcgrady

.github/workflows/publish-snapshot.yml

@@ -16,7 +16,7 @@ jobs:
           - branch-1.3
     steps:
     - name: Checkout repository
-      uses: actions/checkout@2.3.5
+      uses: actions/checkout@v2.3.5
       with:
         ref: ${{ matrix.branch }}
     - name: Cache Maven local repository