Build(deps): bump alpine from 3.21.2 to 3.21.3

Bumps alpine from 3.21.2 to 3.21.3.

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

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

Author: dependabot[bot]

Dockerfile

@@ -12,7 +12,7 @@
 # `default` is the production docker image which cannot be built locally.
 # For local dev and testing purposes, please build and use the `dev` docker image.
 
-FROM docker.mirror.hashicorp.services/alpine:3.21.2 AS dev
+FROM docker.mirror.hashicorp.services/alpine:3.21.3 AS dev
 
 RUN addgroup vault && \
     adduser -S -G vault vault
@@ -24,7 +24,7 @@ USER vault
 ENTRYPOINT ["/vault-k8s"]
 
 # This target creates a production release image for the project.
-FROM docker.mirror.hashicorp.services/alpine:3.21.2 AS default
+FROM docker.mirror.hashicorp.services/alpine:3.21.3 AS default
 
 # PRODUCT_VERSION is the tag built, e.g. v0.1.0
 # PRODUCT_REVISION is the git hash built