Disable CI for PG versions that fail now.

I'll eventually fix the build for all PG versions and re-enable the tests.

Author: Antonin Houska

.github/workflows/regression.yml

@@ -14,8 +14,6 @@ jobs:
       matrix:
         pgversion:
           - 15
-          - 14
-          - 13
 
     env:
       PGVERSION: ${{ matrix.pgversion }}