build: Update branch names Recently the master branch was frozen, and a new releases/v5.x branch was created to keep the maintenance of the V5 version. The new default branch is now main.

This change update all GitHub Workflows to align with the new
branch strategy.

Signed-off-by: Paulo Gomes <[e-mail]>

.github/workflows/cifuzz.yml

···
 on: 
   pull_request:
     branches:
-      - master
+      - main
 
 permissions: {}
 

.github/workflows/codeql.yml

···
-name: "CodeQL"
+name: CodeQL
 on:
   push:
     branches:
-    - "master"
-    - "v6-exp"
+    - releases/v5.x
+    - main
   pull_request:
 
   schedule:

.github/workflows/git.yml

···
 on:
   push:
     branches:
-    - "master"
-    - "v6-exp"
+    - releases/v5.x
+    - main
   pull_request:
 
 permissions: {}

.github/workflows/pr-validation.yml

···
-name: 'PR Validation'
+name: PR Validation
 on:
   pull_request:
     types:

.github/workflows/stale-issues-bot.yaml

···
-name: "stale issues bot"
+name: stale issues bot
 on:
   schedule:
   - cron: "0 7 * * *"

.github/workflows/test.yml

···
 on: 
   push:
     branches:
-    - "master"
-    - "v6-exp"
+    - releases/v5.x
+    - main
   pull_request:
 
 permissions: {}

CONTRIBUTING.md

···
 <package>: <subpackage>, <what changed>. [Fixes #<issue-number>]
 ```
 
-[discord server]: https://discord.gg/6CG7M6wF
+[discord server]: https://discord.gg/8hrxYEVPE5
 [StackOverflow go-git tag]: https://stackoverflow.com/questions/tagged/go-git
 [Issues]: https://github.com/go-git/go-git/issues
 [official git implementation]: https://github.com/git/git