CI(neon-build): enable sccache

.github/workflows/build_and_test.yml

@@ -214,6 +214,9 @@ jobs:
       BUILD_TYPE: ${{ matrix.build_type }}
       GIT_VERSION: ${{ github.event.pull_request.head.sha || github.sha }}
       BUILD_TAG: ${{ needs.tag.outputs.build-tag }}
+      SCCACHE_BUCKET: neon-github-dev
+      SCCACHE_REGION: eu-central-1
+      SCCACHE_S3_KEY_PREFIX: sccache
 
     steps:
       - name: Fix git ownership

Dockerfile

@@ -32,9 +32,9 @@ ARG BUILD_TAG
 # Enable https://github.com/mozilla/sccache to cache Rust crates' compilation results in Docker builds.
 # Set up sccache to use an AWS S3 bucket for cache results, to reuse it between `docker build` invocations.
 ARG RUSTC_WRAPPER
+ARG SCCACHE_BUCKET=neon-github-dev
 ARG SCCACHE_REGION=eu-central-1
 ARG SCCACHE_S3_KEY_PREFIX=sccache
-ARG SCCACHE_BUCKET=neon-github-dev
 ARG AWS_ACCESS_KEY_ID
 ARG AWS_SECRET_ACCESS_KEY