feat: switch default branch to main

Due to local tooling updates, all the other Dokku repositories are converging on 'main' as the default. This makes my local workflows for interacting with this repository annoying as I need to remember if the repo uses main or master. As such, the default branch is moving to main to reduce cognitive overhead while I maintain the repository.

.github/workflows/build.yaml

@@ -5,10 +5,10 @@ name: build
 on:
   pull_request:
     branches:
-      - '*'
+      - "*"
   push:
     branches:
-      - 'master'
+      - "main"
 
 jobs:
   docker:

.github/workflows/lint.yaml

@@ -8,7 +8,7 @@ on:
       - "*"
   push:
     branches:
-      - "master"
+      - "main"
 
 jobs:
   hadolint:

.github/workflows/trivy-analysis.yaml

@@ -5,7 +5,7 @@ name: trivy-analysis
 on:
   push:
     branches:
-      - master
+      - "main"
   pull_request:
 
 jobs:
@@ -23,13 +23,13 @@ jobs:
       - name: Run Trivy vulnerability scanner
         uses: aquasecurity/trivy-action@master
         with:
-          image-ref: 'docker.io/dokku/ambassador:${{ github.sha }}'
-          format: 'template'
-          template: '@/contrib/sarif.tpl'
-          output: 'trivy-results.sarif'
-          severity: 'CRITICAL,HIGH'
+          image-ref: "docker.io/dokku/ambassador:${{ github.sha }}"
+          format: "template"
+          template: "@/contrib/sarif.tpl"
+          output: "trivy-results.sarif"
+          severity: "CRITICAL,HIGH"
 
       - name: Upload Trivy scan results to GitHub Security tab
         uses: github/codeql-action/upload-sarif@v3
         with:
-          sarif_file: 'trivy-results.sarif'
+          sarif_file: "trivy-results.sarif"