Update google-api-core requirement from ~=2.15.0 to ~=2.16.0

Updates the requirements on [google-api-core](https://github.com/googleapis/python-api-core) to permit the latest version.
- [Release notes](https://github.com/googleapis/python-api-core/releases)
- [Changelog](https://github.com/googleapis/python-api-core/blob/main/CHANGELOG.md)
- [Commits](googleapis/python-api-core@v2.15.0...v2.16.0)

---
updated-dependencies:
- dependency-name: google-api-core
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>

requirements.txt

@@ -40,7 +40,7 @@ executing~=2.0.0
 fastjsonschema~=2.19.0
 fonttools~=4.47.0
 future==0.18.3
-google-api-core~=2.15.0
+google-api-core~=2.16.0
 google-auth~=2.27.0
 googleapis-common-protos~=1.62.0
 h5netcdf~=1.3.0