Package pg_duckdb for review

[olirice]

This task is to package (but not ship) pg_duckdb to evaluate it locally and check interop with Supabase S3 compatible Storage

[samrose]

This is in process about 70%

Ran into some issues with the Makefile assumptions about deps and installation, and so will need to patch that on build

[docteurklein]

Hi! Are you writing a nix derivation for pg_duckdb? Because I tried here without success.

The compilation works fine, but the installPhase seems to fail with:

pg_duckdb> /nix/store/ifzwv2xqwdnv1gz87rxkizi67py5p3vj-coreutils-9.4/bin/mkdir -p '/nix/store/wwp41hdca4bwpsczq47a7bzj19pr63fz-postgresql-16.2/share/postgresql/extension'
pg_duckdb> /nix/store/ifzwv2xqwdnv1gz87rxkizi67py5p3vj-coreutils-9.4/bin/mkdir -p '/nix/store/wwp41hdca4bwpsczq47a7bzj19pr63fz-postgresql-16.2/share/postgresql/extension'
pg_duckdb> /nix/store/ifzwv2xqwdnv1gz87rxkizi67py5p3vj-coreutils-9.4/bin/install -c -m 755  pg_duckdb.so '/nix/store/r0kvgrg6j84jwva3vcisvc6ggwbvwmi4-postgresql-16.2-lib/lib/pg_duckdb.so'
pg_duckdb> /nix/store/ifzwv2xqwdnv1gz87rxkizi67py5p3vj-coreutils-9.4/bin/install: cannot create regular file '/nix/store/r0kvgrg6j84jwva3vcisvc6ggwbvwmi4-postgresql-16.2-lib/lib/pg_duckdb.so': Permission denied
pg_duckdb> make: *** [/nix/store/wwp41hdca4bwpsczq47a7bzj19pr63fz-postgresql-16.2/lib/pgxs/src/makefiles/../../src/Makefile.shlib:422: install-lib-shared] Error 1