build: bump golang from 1.18.3-alpine3.16 to 1.20.4-alpine3.16 (#433)

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

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

Dockerfile

@@ -1,5 +1,5 @@
 ## Build image ##
-FROM golang:1.18.3-alpine3.16 as build
+FROM golang:1.20.4-alpine3.16 as build
 
 # System dependencies
 RUN apk add --no-cache make