chore: bump golang from 4c94dfe to b8b5510 in /build/tooling

Bumps golang from `4c94dfe` to `b8b5510`.

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

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

build/tooling/Dockerfile

@@ -1,4 +1,4 @@
-FROM golang:1.20-bullseye@sha256:4c94dfe9567ee66a0ebc35a28f9f939e9ca3a71cb2ab942359887c584da1b28e
+FROM golang:1.20-bullseye@sha256:b8b5510c6754ad783d8b7c3d1da3365c22cd02b25e2c42c94f8d353801c5cd0e
 
 RUN GO111MODULE=on go install sigs.k8s.io/controller-tools/cmd/controller-gen@v0.9.0
 RUN GO111MODULE=on go install k8s.io/code-generator/cmd/conversion-gen@v0.25.4