Bump golang from 1.19 to 1.20 (#36)

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

Dockerfile

@@ -1,4 +1,4 @@
-FROM --platform=$BUILDPLATFORM golang:1.19 AS builder
+FROM --platform=$BUILDPLATFORM golang:1.20 AS builder
 ARG TARGETARCH
 ARG TARGETOS