build: bump library/alpine from 3.20.2 to 3.20.3

Bumps library/alpine from 3.20.2 to 3.20.3.

---
updated-dependencies:
- dependency-name: library/alpine
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

Dockerfile

@@ -1,6 +1,6 @@
 FROM docker.io/nginxproxy/docker-gen:0.14.2 AS docker-gen
 
-FROM docker.io/library/alpine:3.20.2
+FROM docker.io/library/alpine:3.20.3
 
 ARG GIT_DESCRIBE="unknown"
 ARG ACMESH_VERSION=3.0.7