Updates checkout plugin for github actions to v4. Can not update the
version for check-sql-snapshots since new plugin causes below error in
the docker image this step is using . Please refer to:
https://github.com/citusdata/citus/actions/runs/9286197994/job/25552373953
Error:
```
/__e/node20/bin/node: /lib/x86_64-linux-gnu/libm.so.6: version `GLIBC_2.27' not found (required by /__e/node20/bin/node)
/__e/node20/bin/node: /lib/x86_64-linux-gnu/libc.so.6: version `GLIBC_2.28' not found (required by /__e/node20/bin/node)
/__e/node20/bin/node: /lib/x86_64-linux-gnu/libc.so.6: version `GLIBC_2.25' not found (required by /__e/node20/bin/node)
```
(cherry picked from commit 2874d7af46)
Gürkan İndibay
Gokhan Gulbiz