chore(deps): bump golang from 1.18.1-buster to 1.18.2-buster in /build

Bumps golang from 1.18.1-buster to 1.18.2-buster.

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

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

build/Dockerfile

@@ -1,5 +1,5 @@
 # Build golang app
-FROM golang:1.18.1-buster AS builder
+FROM golang:1.18.2-buster AS builder
 
 WORKDIR /go/src/github.com/klaasjand/lagoon