ci: update workflow to Go 1.22 and modern actions

- Use go-version-file to read from go.mod
- Upgrade to actions/checkout@v4 and actions/setup-go@v5
- Remove deprecated dep/Gopkg.toml logic

Made-with: Cursor

Author: grantmd

.github/workflows/go.yml

@@ -7,22 +7,13 @@ jobs:
     runs-on: ubuntu-latest
     steps:
 
-    - name: Set up Go 1.13
-      uses: actions/setup-go@v1
-      with:
-        go-version: 1.13
-      id: go
-
-    - name: Check out code into the Go module directory
-      uses: actions/checkout@v1
+    - name: Check out code
+      uses: actions/checkout@v4
 
-    - name: Get dependencies
-      run: |
-        go get -v -t -d ./...
-        if [ -f Gopkg.toml ]; then
-            curl https://raw.githubusercontent.com/golang/dep/master/install.sh | sh
-            dep ensure
-        fi
+    - name: Set up Go
+      uses: actions/setup-go@v5
+      with:
+        go-version-file: go.mod
 
     - name: Build
       run: go build -v .