[KYUUBI #1901] [GA] Fix checkout version

<!--
Thanks for sending a pull request!

Here are some tips for you:
  1. If this is your first time, please read our contributor guidelines: https://kyuubi.readthedocs.io/en/latest/community/contributions.html
  2. If the PR is related to an issue in https://github.com/apache/incubator-kyuubi/issues, add '[KYUUBI #XXXX]' in your PR title, e.g., '[KYUUBI #XXXX] Your PR title ...'.
  3. If the PR is unfinished, add '[WIP]' in your PR title, e.g., '[WIP][KYUUBI #XXXX] Your PR title ...'.
-->

### _Why are the changes needed?_
<!--
Please clarify why the changes are needed. For instance,
  1. If you add a feature, you can talk about the use case of it.
  2. If you fix a bug, you can clarify why it is a bug.
-->

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

276380cf [Fu Chen] fix checkout version

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

.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