chore(ci): disable optional CRC32 request checksum for R2 signature sync

AWS CLI v1 (current botocore) defaults request checksums to CRC32,
which Cloudflare R2 may reject on single-part PutObject uploads. Set
AWS_REQUEST_CHECKSUM_CALCULATION=when_required, matching the pattern
used by telegraf and influxctl. Integrity remains protected via the
SigV4 x-amz-content-sha256 hash and R2's MD5 ETag.

Author: tkyocum

.circleci/config.yml

@@ -280,6 +280,8 @@ jobs:
   packages-upload-signatures:
     docker:
       - image: cimg/python:3.12.3
+    environment:
+      AWS_REQUEST_CHECKSUM_CALCULATION: when_required
     steps:
       - attach_workspace:
           at: /tmp/workspace