Bump alpine from 3.14 to 3.15.0 (#238)

* Bump alpine from 3.14 to 3.15.0

Bumps alpine from 3.14 to 3.15.0.

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

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

* Generalize Alpine version in Dockerfile

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: Marc Auberer <marc.auberer@chillibits.com>

Dockerfile

@@ -1,5 +1,5 @@
 # WARNING: This Dockerfile is not meant to be used to build the Docker image manually
-FROM alpine:3.14
+FROM alpine:3.15
 
 # Set env variables
 ENV PATH="/cg:${PATH}"
@@ -31,4 +31,4 @@ COPY predefined-services/ /cg/predefined-services/
 RUN chmod +x /cg/cg
 
 # Set entrypoint
-ENTRYPOINT [ "cg" ]
+ENTRYPOINT [ "cg" ]