build: add vulnerability testing using govulncheck

.github/workflows/build.yml

@@ -233,6 +233,19 @@ jobs:
           # Optional: version of golangci-lint to use in form of v1.2 or v1.2.3 or `latest` to use the latest version
           version: latest
 
+      # Run govulncheck on the latest go version, the one we build binaries with
+      - name: Install Go
+        uses: actions/setup-go@v3
+        with:
+          go-version: 1.19
+          check-latest: true
+
+      - name: Install govulncheck
+        run: go install golang.org/x/vuln/cmd/govulncheck@latest
+
+      - name: Scan for vulnerabilities
+        run: govulncheck ./...
+
   android:
     if: ${{ github.repository == 'rclone/rclone' || github.event.inputs.manual }}
     timeout-minutes: 30