fix awk variable

Signed-off-by: William Woodruff <william@trailofbits.com>

Author: woodruffw

.github/workflows/ci.yml

@@ -65,7 +65,7 @@ jobs:
       - name: test (timestamp-authority)
         if: ${{ matrix.conf.os == 'ubuntu-latest' }}
         run: |
-          SIGSTORE_TIMESTAMP_VERSION=$(grep "github.com/sigstore/timestamp-authority" .github/go.mod | awk '{print $2}')
+          SIGSTORE_TIMESTAMP_VERSION=$(grep "github.com/sigstore/timestamp-authority" .github/go.mod | awk '{print $3}')
           wget https://github.com/sigstore/timestamp-authority/releases/download/${SIGSTORE_TIMESTAMP_VERSION}/timestamp-server-linux-amd64 -O /tmp/timestamp-server
           chmod +x /tmp/timestamp-server
           # Run the TSA in background