Upgrade Alpine base image to 3.22 to fix OpenSSL CVE (#727)

Updates deployment-operator Dockerfile FROM alpine:3.21 to alpine:3.22
to address OpenSSL vulnerability (CVE: NULL pointer dereference in CMS
EnvelopedData processing).

This upgrade brings libcrypto3 from 3.3.6-r0 to 3.5.6-r0, which includes
the required security fix (3.3.7-r0+) for the vulnerability affecting
CMS_decrypt() operations on untrusted input.

Verified: Docker build successful with libcrypto3 3.5.6-r0 installed.

Co-authored-by: Michael Guarino <mjg@plural.sh>

Author: plural-copilot[bot]

Dockerfile

@@ -28,7 +28,7 @@ RUN curl -L https://get.helm.sh/helm-${HELM_VERSION}-linux-${TARGETARCH}.tar.gz
     mv linux-${TARGETARCH}/helm /usr/local/bin/helm && \
     chmod +x /usr/local/bin/helm
 
-FROM alpine:3.21
+FROM alpine:3.22
 WORKDIR /workspace
 
 # Upgrade all packages to get the latest security fixes