Remove stage 1 build

I don't think this is required, and it causes issues for CI
Re-enable macOS CI

Author: lrettig

.github/workflows/build_and_release.yml

@@ -20,7 +20,7 @@ jobs:
       matrix:
         os:
           - ubuntu-latest
-          # - macos-latest
+          - macos-latest
 
     steps:
       - name: Free Disk Space (Ubuntu)

build.sh

@@ -6,5 +6,4 @@ source config.sh
 
 # Will create component archives (dists) ./rust/build/dist
 cd rust
-CARGO_TARGET_RISCV32EM_ATHENA_ZKVM_ELF_RUSTFLAGS="-Cpasses=loweratomic" ./x build
 CARGO_TARGET_RISCV32EM_ATHENA_ZKVM_ELF_RUSTFLAGS="-Cpasses=loweratomic" ./x build --stage 2