Ensure go 1.20 is used rather than 1.2 due to yaml parsing

.github/workflows/tfplugindocs.yml

@@ -14,7 +14,7 @@ jobs:
       - name: Set up Go
         uses: actions/setup-go@v4
         with:
-          go-version: 1.20
+          go-version: "1.20"
       - name: Check out code into the Go module directory
         uses: actions/checkout@v3
       - name: Get dependencies