fix(ci): use forge-build in dockerfile (ethereum-optimism#12377)

Updates the dockerfile for building contracts-bedrock to use
just forge-build instead of just build since just build now does
a few other things for the sake of devex.

.circleci/config.yml

@@ -1369,7 +1369,7 @@ jobs:
           name: Build contracts
           environment:
             FOUNDRY_PROFILE: ci
-          command: just build
+          command: just forge-build
           working_directory: packages/contracts-bedrock
       - run:
           name: Publish artifacts

ops/docker/Dockerfile.packages

@@ -31,7 +31,7 @@ COPY .gitmodules ./.gitmodules
 
 RUN git submodule update --init --recursive \
     && cd packages/contracts-bedrock \
-    && just build \
+    && just forge-build \
     && echo $(git rev-parse HEAD) > .gitcommit
 
 FROM --platform=linux/amd64 debian:bookworm-20240812-slim as contracts-bedrock