fix(deps): bump golang from 1.21.1 to 1.21.2 (#323)

Bumps golang from 1.21.1 to 1.21.2.

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

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

Dockerfile

@@ -1,6 +1,6 @@
 ARG MODE=client
 
-FROM golang:1.21.1 as builder
+FROM golang:1.21.2 as builder
 ARG MODE
 ENV MODE="$MODE"
 ENV MODULE=github.com/soerenschneider/dyndns