Use US standard S3 region

Dependencies

• [2] GTUZLZRH Add an S3-backed binary cache store
• [3] B2L4T3X6 Sync with Nix
• [4] SOB276BA Keep some statistics for the binary cache stores
• [5] EOO4EFWD Use a single BinaryCacheStore for all threads

Change contents

• replacement in src/hydra-queue-runner/s3-binary-cache-store.cc at line 47
  [2.2486]→[2.2486:2528](∅→∅)
  − res->region = Aws::Region::EU_WEST_1;
  [2.2486]

  [2.2528]
  + res->region = Aws::Region::US_EAST_1;
• replacement in src/hydra-queue-runner/s3-binary-cache-store.cc at line 69
  [2.3325]→[2.3325:3443](∅→∅)
  − .WithLocationConstraint(

  − Aws::S3::Model::BucketLocationConstraint::eu_west_1))));
  [2.3325]

  [2.3443]
  + /* .WithLocationConstraint(

  + Aws::S3::Model::BucketLocationConstraint::US) */ )));