Summary:
The yugabyte-db clean build is failing on some macos builds due to some warnings that come during pg_parquet build.
This diff sets the CFLAGS to ignore pg_parquet build warning in all builds including macos.
Jira: DB-18184

Test Plan:
On macos (version 15.5,Chip - Apple M4 Pro)
```
cd ~/code/yugabyte-db
rm -rf build/
./yb_build.sh --clean
```

Reviewers: ashetkar, jason

Reviewed By: jason

Subscribers: yql, arybochkin

Tags: #jenkins-ready

Differential Revision: https://phorge.dev.yugabyte.com/D46586