Bump alpine from 3.18 to 3.19 in /container

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] <[email protected]>

container/Dockerfile

@@ -5,7 +5,7 @@
 # $ docker run --rm -i hadolint/hadolint < Dockerfile
 
 # ---------- build taganaka/SpeedTest binary ----------
-FROM alpine:3.18 as compiler
+FROM alpine:3.19 as compiler
 
 # install build framework and libraries
 # hadolint ignore=DL3018
@@ -21,7 +21,7 @@ RUN git clone https://github.com/taganaka/SpeedTest.git . \
   && make
 
 # --------- build application container ----------
-FROM alpine:3.18 as runtime
+FROM alpine:3.19 as runtime
 
 # install necessary packages and fonts
 # hadolint ignore=DL3018