chore(go): Update code generation CI to check Go polymorph code

.github/actions/polymorph_codegen/action.yml

@@ -141,6 +141,12 @@ runs:
       run: |
         make polymorph_dotnet ${{ steps.dependencies.outputs.PROJECT_DEPENDENCIES }}
 
+    - name: Regenerate Go code using smithy-dafny
+      working-directory: ./${{ inputs.library }}
+      shell: bash
+      run: |
+        make polymorph_go
+
     - name: Check regenerated code against commited code
       # Composite action inputs seem to not actually support booleans properly for some reason
       if: inputs.diff-generated-code == 'true'

.github/workflows/ci_codegen.yml

@@ -18,6 +18,7 @@ jobs:
         # in this workflow
         dotnet-version: ["6.0.x"]
         os: [ubuntu-22.04]
+        go-version: [1.23]
     runs-on: ${{ matrix.os }}
     defaults:
       run:
@@ -48,6 +49,15 @@ jobs:
         with:
           dotnet-version: ${{ matrix.dotnet-version }}
 
+      - name: Install Go
+        uses: actions/setup-go@v5
+        with:
+          go-version: ${{ matrix.go-version }}
+
+      - name: Install Go imports
+        run: |
+          go install golang.org/x/tools/cmd/goimports@latest
+
       - name: Create temporary global.json
         run: echo '{"sdk":{"rollForward":"latestFeature","version":"6.0.0"}}' > ./global.json