Bump alpine from 3.18 to 3.19 (#100)

Bumps alpine from 3.18 to 3.19.

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

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

Dockerfile

@@ -5,7 +5,7 @@ WORKDIR /app
 COPY . /app/
 RUN CGO_ENABLED=0 GOOS=linux go build -ldflags '-extldflags "-static"' -o /app/flagger-k6-webhook cmd/main.go
 
-FROM alpine:3.18
+FROM alpine:3.19
 
 COPY --from=build /app/flagger-k6-webhook /usr/bin/flagger-k6-webhook
 COPY --from=grafana/k6 /usr/bin/k6 /usr/bin/k6