use main branch in workflows instead of master

Author: Ricus Nortje

.github/workflows/build.yaml

@@ -3,11 +3,11 @@ name: Build package
 on:
   push:
     branches:
-    - master
+    - main
 
   pull_request:
     branches:
-    - master
+    - main
 
 concurrency: build-${{ github.ref }}
 

.github/workflows/publish.yaml

@@ -57,7 +57,7 @@ jobs:
         cache-from: |
           type=gha,scope=sha-${{ github.sha }}
           type=gha,scope=${{ github.ref_name }}
-          type=gha,scope=${{ github.base_ref || 'master' }}
+          type=gha,scope=${{ github.base_ref || 'main' }}
           type=gha,scope=main
         cache-to: |
           type=gha,scope=sha-${{ github.sha }},mode=max

.github/workflows/release.yaml

@@ -38,8 +38,8 @@ jobs:
     steps:
     - name: Validate ref
       run: |
-        if [ "${{ github.ref }}" != refs/heads/master ]; then
-          >&2 echo "Invalid ref: ${{ github.ref }} (expected: refs/heads/master)"
+        if [ "${{ github.ref }}" != refs/heads/main ]; then
+          >&2 echo "Invalid ref: ${{ github.ref }} (expected: refs/heads/main)"
           exit 1
         fi