Bump alpine from 3.19 to 3.20

Bumps alpine from 3.19 to 3.20.

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

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

Dockerfile

@@ -17,7 +17,7 @@ WORKDIR $GOPATH/src/simapp
 COPY . .
 RUN make all
 
-FROM alpine:3.19 AS simapp
+FROM alpine:3.20 AS simapp
 
 LABEL description="Aether open source 5G Core Network" \
     version="Stage 3"