Extended attributes in binaries #803

While working on the build scripts, I discovered that some of our binaries have extended attributes:

For example this file has an xattr:

xattr -l /Volumes/Postgres-2.8.1-13/Postgres.app/Contents/Versions/13/bin/postgres
com.apple.provenance: 

but this one does not:

xattr -l /Volumes/Postgres-2.8.1-13-14-15-16-17/Postgres.app/Contents/Versions/13/bin/postgres

This one has a different one:

xattr -l /Volumes/Postgres-2.8.1-13-14-15-16-17/Postgres.app/Contents/Versions/13/bin/pg_waldump 
com.apple.quarantine: 0283;67b62510;;DD999524-DADA-40CE-B031-20B20A41E650

I'm not sure where these are coming from. Probably a result of using cp -a to copy the binaries.
I discovered these xattrs when I replaced cp -a with rsync -a in 050cdda. The latter does not include the xattrs.

I assume it is better not to include them. I believe xattrs are used for some code signatures of shell scripts, but I think this happens after the copy-binaries phase. I think we should not include the com.apple.quarantine and com.apple.provenance xattrs.