Bump alpine from 3.18 to 3.19 in /build/cert-creator

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>

build/cert-creator/Dockerfile

@@ -1,4 +1,4 @@
-FROM alpine:3.18
+FROM alpine:3.19
 
 RUN apk update && \
   apk add --no-cache openssl && \