treewide: add missing meta.homepage with source git repository

Added homepage where missing, where the sources are pulled from:
- https://github.com
- https://git.sr.ht
- https://gitlab.com
- https://invent.kde.org
- https://codeberg.org
- https://gitlab.gnome.org
- https://gitlab.freedesktop.org
- https://git.FreeBSD.org
- https://salsa.debian.org
- https://git.tvdr.de
- https://git.suckless.org

pkgs/servers/sql/postgresql/ext/pg_similarity.nix

@@ -36,6 +36,7 @@ postgresqlBuildExtension {
       is tightly integrated in the RDBMS in the sense that it defines operators so instead of the traditional
       operators (= and <>) you can use ~~~ and ~!~ (any of these operators represents a similarity function).
     '';
+    homepage = "https://github.com/eulerto/pg_similarity";
     platforms = postgresql.meta.platforms;
     license = lib.licenses.bsd3;
     maintainers = [ ];

pkgs/servers/sql/postgresql/ext/pgjwt.nix

@@ -38,6 +38,7 @@ postgresqlBuildExtension (finalAttrs: {
     longDescription = ''
       sign() and verify() functions to create and verify JSON Web Tokens.
     '';
+    homepage = "https://github.com/michelp/pgjwt";
     license = lib.licenses.mit;
     platforms = postgresql.meta.platforms;
     maintainers = with lib.maintainers; [ spinus ];