chore: vendor dependencies (GoogleCloudPlatform#4)

Author: kurtisvg

.github/workflows/tests.yaml

@@ -31,16 +31,6 @@ jobs:
           go-version: "1.18"
       - name: Checkout code
         uses: actions/checkout@v3
-      # TODO remove this step and the following when the repo is public
-      - name: Checkout AlloyDB connector
-        uses: actions/checkout@v3
-        with:
-          repository: "googlecloudplatform/alloydb-go-connector"
-          path: "alloydb-go-connector"
-          token: ${{ secrets.GH_PAT }}
-      - name: Point to local connector
-        run: |
-          go mod edit -replace=cloud.google.com/go/alloydbconn=./alloydb-go-connector
       - name: Run tests
         run: |
           go test -v -race -cover -short ./...