Bump golang from 1.19 to 1.20 in /images/scorecard-test-kuttl

Bumps golang from 1.19 to 1.20.

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

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

images/scorecard-test-kuttl/Dockerfile

@@ -1,5 +1,5 @@
 # Build the scorecard-test-kuttl binary
-FROM --platform=$BUILDPLATFORM golang:1.19 as builder
+FROM --platform=$BUILDPLATFORM golang:1.20 as builder
 ARG TARGETARCH
 ARG BUILDPLATFORM