fix: Dockerfile to reduce vulnerabilities

The following vulnerabilities are fixed with an upgrade:
- https://snyk.io/vuln/SNYK-ALPINE319-OPENSSL-8235202
- https://snyk.io/vuln/SNYK-ALPINE319-OPENSSL-8235202

Dockerfile

@@ -1,5 +1,5 @@
 # syntax=docker/dockerfile:1.2
-FROM alpine:3.19
+FROM alpine:3.21.0
 
 RUN apk --no-cache --no-progress add ca-certificates tzdata \
     && rm -rf /var/cache/apk/*