Bump ubuntu from f9d633f to 77906da in /images/toolbox

Bumps ubuntu from `f9d633f` to `77906da`.

---
updated-dependencies:
- dependency-name: ubuntu
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

images/toolbox/Dockerfile

@@ -12,7 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-FROM ubuntu:22.04@sha256:f9d633ff6640178c2d0525017174a688e2c1aef28f0a0130b26bd5554491f0da
+FROM ubuntu:22.04@sha256:77906da86b60585ce12215807090eb327e7386c8fafb5402369e421f44eff17e
 
 LABEL maintainer="Antrea <projectantrea-dev@googlegroups.com>"
 LABEL description="A Docker image with useful tools (for networking) based on Ubuntu"