chore(deps): update golang docker tag to v1.26

Signed-off-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

Dockerfile

@@ -12,7 +12,7 @@ RUN cargo install --path .
 FROM runtime
 COPY --from=builder /usr/local/cargo/bin/ovsinit /usr/local/bin/ovsinit
 
-FROM golang:1.21@sha256:4746d26432a9117a5f58e95cb9f954ddf0de128e9d5816886514199316e4a2fb AS ovn-kubernetes
+FROM golang:1.26@sha256:dd25c49df34a6ec745f1dd59593478d067679e8e8fb1e44b326d8b9e2d348777 AS ovn-kubernetes
 RUN apt-get update && \
     apt-get install --no-install-recommends -y \
         quilt