hardcode location for POSTGRES librarys on macOS
hardcode location for POSTGRES librarys on macOS

- Without this, and depending on system configuration, cmake's find_library would decide that these libraries are part of the system and not include them in the package build
- For example: `PQ_LIB:FILEPATH=/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.15.sdk/usr/lib/libpq.tbd`

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