Restrict CI and release task to pgjdbc/r2dbc-postgresql repo

Prevents jobs from running (and failing) on forks

[#347]

Author: mrotteveel

.github/workflows/ci.yml

@@ -9,6 +9,7 @@ on:
 
 jobs:
   build:
+    if: github.repository == 'pgjdbc/r2dbc-postgresql'
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v2

.github/workflows/release.yml

@@ -9,6 +9,7 @@ on:
 
 jobs:
   release:
+    if: github.repository == 'pgjdbc/r2dbc-postgresql'
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v2