actions: work around broken macos postgresql

Homebrew started distributing versioned postgresql packages with
a non-standard directory layout that breaks cmake's scripts for
finding postgresql. Work around the issue.
See actions/runner-images#6176.

Author: lonvia

.github/workflows/ci.yml

@@ -16,7 +16,12 @@ jobs:
         run: |
           brew install lua boost postgis pandoc
           pip3 install psycopg2 behave
+          pg_ctl -D /usr/local/var/postgres init
           pg_ctl -D /usr/local/var/postgres start
+          # Work around homebrew postgresql installation screw-up, see
+          # https://github.com/actions/runner-images/issues/6176
+          ln -s $(pg_config --libdir)/* /usr/local/lib/ || true
+          ln -s $(pg_config --includedir)/* /usr/local/include/
         shell: bash
 
       - name: Setup database