Update GitHub Actions workflows

- Pin to full -length commit hash
- Add master alongside main

.github/workflows/go-test.yml

@@ -4,9 +4,11 @@ on:
   push:
     branches:
       - main
+      - master
   pull_request:
     branches:
       - main
+      - master
 
 permissions:
   contents: read
@@ -34,15 +36,15 @@ jobs:
 
     steps:
       - name: Checkout Source
-        uses: actions/checkout@v4
+        uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
 
       - name: Set up Go 1.25
-        uses: actions/setup-go@v4
+        uses: actions/setup-go@44694675825211faa026b3c33043df3e48a5fa00 # v6.0.0
         with:
           go-version: '1.25'
 
       - name: Cache Go modules
-        uses: actions/cache@v3
+        uses: actions/cache@0057852bfaa89a56745cba8c7296529d2fc39830 # v4.3.0
         with:
           path: |
             ~/go/pkg/mod