ops: use alpine:3.14 with foundry image

.changeset/rude-ads-try.md

+---
+'@eth-optimism/foundry': patch
+---
+
+Use alpine:3.14

ops/docker/foundry/Dockerfile

-from alpine as build-environment
+from alpine:3.14 as build-environment
 WORKDIR /opt
 RUN apk add clang lld curl build-base linux-headers git \
     && curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs > rustup.sh \
@@ -16,7 +16,7 @@ RUN source $HOME/.profile && cargo build --release \
     && strip /opt/foundry/target/release/cast \
     && strip /opt/foundry/target/release/anvil
 
-from alpine as foundry-client
+from alpine:3.14 as foundry-client
 ENV GLIBC_KEY=https://alpine-pkgs.sgerrand.com/sgerrand.rsa.pub
 ENV GLIBC_KEY_FILE=/etc/apk/keys/sgerrand.rsa.pub
 ENV GLIBC_RELEASE=https://github.com/sgerrand/alpine-pkg-glibc/releases/download/2.35-r0/glibc-2.35-r0.apk