🔧 chore(docker): bump cosign and trivy alpine pins to current mirror versions

cosign jumped from 2.4.3-r11 to 2.4.3-r12 and trivy from 0.69.3-r1 to
0.69.3-r2 in the upstream alpine mirrors, which broke local docker
builds with "breaks: world[cosign=...]" / "breaks: world[trivy=...]"
errors. Match the current pins so docker build works again.

Author: s-b-e-n-s-o-n

Dockerfile

@@ -24,8 +24,8 @@ RUN apk add --no-cache \
     su-exec=0.3-r0 \
     tini=0.19.0-r3 \
     tzdata=2026a-r0 \
-    && apk add --no-cache cosign=2.4.3-r11 \
-    && apk add --no-cache --repository=https://dl-cdn.alpinelinux.org/alpine/edge/testing trivy=0.69.3-r1 \
+    && apk add --no-cache cosign=2.4.3-r12 \
+    && apk add --no-cache --repository=https://dl-cdn.alpinelinux.org/alpine/edge/testing trivy=0.69.3-r2 \
     && apk upgrade --no-cache zlib \
     && mkdir /store && chown node:node /store