(maint) Update github actions to account for 7.x branch

Puppet 6.x will be end of life on February 28, 2023 and Puppet 7.x will become the long term support (LTS) branch. In preparation for this, a new Puppet 7.x branch will be created and Puppet's GitHub Actions & protection rules must be updated. This PR updates Puppet's GitHub Actions to account for 7.x being the new LTS branch.

Author: AriaXLi

.github/workflows/checks.yaml

@@ -3,9 +3,9 @@ name: Checks
 
 on:
   push:
-    branches: [main]
+    branches: [7.x]
   pull_request:
-    branches: [main]
+    branches: [7.x]
 
 permissions:
   contents: read

.github/workflows/rspec_tests.yaml

@@ -3,9 +3,9 @@ name: RSpec tests
 
 on:
   push:
-    branches: [main]
+    branches: [7.x]
   pull_request:
-    branches: [main]
+    branches: [7.x]
 
 permissions:
   contents: read

.github/workflows/snyk_monitor.yaml

@@ -3,7 +3,7 @@ name: Snyk Monitor
 on:
   push:
     branches:
-      - main
+      - 7.x
 permissions:
   contents: read