Switch all master references to main

.github/workflows/test_buildx_and_publish.yml

@@ -90,9 +90,9 @@ jobs:
  tags: ${{ steps.calculatetags.outputs.tags }}
 
  # https://github.com/peter-evans/dockerhub-description
- # Note that we only update the description with the master branch version.
+ # Note that we only update the description with the main branch version.
  - name: Set Docker Hub description from README.md
- if: github.ref == 'refs/heads/master'
+ if: github.ref == 'refs/heads/main'
  uses: peter-evans/dockerhub-description@v3
  with:
  username: ${{ secrets.DOCKERHUB_USERNAME }}

README.md

@@ -1,7 +1,7 @@
 Test files for external Moodle tests
 ====================================
 
-[![Test and publish](https://github.com/moodlehq/moodle-exttests/actions/workflows/test_buildx_and_publish.yml/badge.svg?branch=master)](https://github.com/moodlehq/moodle-php-apache/actions/workflows/test_buildx_and_publish.yml)
+[![Test and publish](https://github.com/moodlehq/moodle-exttests/actions/workflows/test_buildx_and_publish.yml/badge.svg?branch=main)](https://github.com/moodlehq/moodle-php-apache/actions/workflows/test_buildx_and_publish.yml)
 
 **It's really important to keep these files completely unmodified in order to obtain coherent test results in all supported Moodle versions.**