postgresql: add support to PL/Python

pkgs/servers/sql/postgresql/default.nix

@@ -25,6 +25,10 @@ let
       , nukeReferences, patchelf, llvmPackages
       , makeRustPlatform, buildPgxExtension, cargo, rustc
 
+      # PL/Python
+      , pythonSupport ? false
+      , python3
+
       # detection of crypt fails when using llvm stdenv, so we add it manually
       # for <13 (where it got removed: https://github.com/postgres/postgres/commit/c45643d618e35ec2fe91438df15abd4f3c0d85ca)
       , libxcrypt
@@ -63,6 +67,7 @@ let
       ++ lib.optionals lz4Enabled [ lz4 ]
       ++ lib.optionals zstdEnabled [ zstd ]
       ++ lib.optionals enableSystemd [ systemd ]
+      ++ lib.optionals pythonSupport [ python3 ]
       ++ lib.optionals gssSupport [ libkrb5 ]
       ++ lib.optionals stdenv'.isLinux [ linux-pam ]
       ++ lib.optionals (!stdenv'.isDarwin) [ libossp_uuid ];
@@ -97,6 +102,7 @@ let
     ] ++ lib.optionals lz4Enabled [ "--with-lz4" ]
       ++ lib.optionals zstdEnabled [ "--with-zstd" ]
       ++ lib.optionals gssSupport [ "--with-gssapi" ]
+      ++ lib.optionals pythonSupport [ "--with-python" ]
       ++ lib.optionals stdenv'.hostPlatform.isRiscV [ "--disable-spinlocks" ]
       ++ lib.optionals jitSupport [ "--with-llvm" ]
       ++ lib.optionals stdenv'.isLinux [ "--with-pam" ];