CICD: Rename the master branch to main (#2774)

Co-authored-by: Tom Limoncelli <tlimoncelli@stackoverflow.com>

.github/workflows/codeql.yml

@@ -13,10 +13,10 @@ name: "CodeQL"
 
 on:
   push:
-    branches: [ "master" ]
+    branches: [ "main" ]
   pull_request:
     # The branches below must be a subset of the branches above
-    branches: [ "master" ]
+    branches: [ "main" ]
   schedule:
     - cron: '32 19 * * 0'
 

.github/workflows/pr_test.yml

@@ -1,7 +1,7 @@
 name: "PR: Run all tests"
 on:
-  # git push origin master:tlim_testpr --force
-  # will trigger a full PR test on the master branch:
+  # git push origin main:tlim_testpr --force
+  # will trigger a full PR test on the main branch:
   # https://github.com/StackExchange/dnscontrol/actions/workflows/pr_test.yml?query=branch%3Atlim_testpr
   push:
     branches: