Stop testing on Rails 6.0.6.

Fixes issue where test env cannot be loaded due to Psych alias parsing.

Author: gregschmit

.github/workflows/pipeline.yml

@@ -16,12 +16,8 @@ jobs:
       fail-fast: false
       matrix:
         ruby: [2.7.5, 3.0.6, 3.1.4, 3.2.2]
-        rails: [6.0.6, 6.1.7, 7.0.4, 7.1.3, 7.2.1, 8.0.2]
+        rails: [6.1.7, 7.0.4, 7.1.3, 7.2.1, 8.0.2]
         exclude:
-          - ruby: 3.1.4
-            rails: 6.0.6
-          - ruby: 3.2.2
-            rails: 6.0.6
           - ruby: 2.7.5
             rails: 7.1.3
           - ruby: 2.7.5