Bump alpine from 3.16.0 to 3.16.1

Bumps alpine from 3.16.0 to 3.16.1.

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

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

Dockerfile

@@ -1,4 +1,4 @@
-FROM alpine:3.16.0
+FROM alpine:3.16.1
 
 ARG POSTSRSD_PACKAGE_VERSION=1.11-r0
 RUN adduser -S postsrsd \