ci: run checkout first so go caching works

.github/workflows/main.yml

@@ -18,21 +18,21 @@ jobs:
     name: Verify
     runs-on: ubuntu-latest
     steps:
+      - uses: actions/checkout@v4
       - name: Install Dafny
         uses: dafny-lang/[email protected]
         with:
           dafny-version: ${{ env.dafny }}
-      - uses: actions/checkout@v4
       - name: Verify
         run: make -j2 verify
   test-support:
     name: Test dafny_go
     runs-on: ubuntu-latest
     steps:
+      - uses: actions/checkout@v4
       - uses: actions/setup-go@v5
         with:
           go-version: ${{ env.go }}
-      - uses: actions/checkout@v4
       - name: Test support library
         run: |
           go test -v -timeout=1m ./dafny_go/... ./eval
@@ -41,14 +41,14 @@ jobs:
     runs-on: ubuntu-latest
     timeout-minutes: 10
     steps:
+      - uses: actions/checkout@v4
       - name: Install Dafny
         uses: dafny-lang/[email protected]
         with:
           dafny-version: ${{ env.dafny }}
       - uses: actions/setup-go@v5
         with:
           go-version: ${{ env.go }}
-      - uses: actions/checkout@v4
       - name: Install goimports
         run: |
           go install golang.org/x/tools/cmd/goimports@latest
@@ -74,14 +74,14 @@ jobs:
     runs-on: macos-latest
     timeout-minutes: 10
     steps:
+      - uses: actions/checkout@v4
       - name: Install Dafny
         uses: dafny-lang/[email protected]
         with:
           dafny-version: ${{ env.dafny }}
       - uses: actions/setup-go@v5
         with:
           go-version: ${{ env.go }}
-      - uses: actions/checkout@v4
       - name: Install goimports
         run: |
           go install golang.org/x/tools/cmd/goimports@latest