Bump golang from 1.20.5 to 1.20.6 in /hack/ccm (#1301)

Bumps golang from 1.20.5 to 1.20.6.

---
updated-dependencies:
- dependency-name: golang
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

hack/ccm/Dockerfile

@@ -18,7 +18,7 @@ ARG TARGETPLATFORM=linux/amd64
 ARG ARCH=amd64
 
 # Build IBM cloud controller manager binary
-FROM golang:1.20.5 AS ccm-builder
+FROM golang:1.20.6 AS ccm-builder
 ARG ARCH
 ARG POWERVS_CLOUD_CONTROLLER_COMMIT
 WORKDIR /build