fix(storage): retry temporary OSS failures

[XiaoHongbo-Hope]

Purpose

OSS can return temporary failures such as HTTP 503. The OSS service classifies these errors as temporary, but the operator had no retry layer, so metadata and data operations failed immediately.

Changes

• Attach OpenDAL RetryLayer to OSS operators with exponential backoff and jitter.
• Support fs.oss.retry.count (default 10) and fs.oss.retry.interval.millisecond (default 500).
• Add a regression test that returns OSS QpsLimitExceeded once and verifies the read succeeds on retry.
• Document the retry options.

Tests

• cargo test --offline -p paimon io::storage_oss::tests
• cargo check --offline -p paimon --no-default-features --features storage-oss
• cargo clippy --offline -p paimon --no-default-features --features storage-oss -- -D warnings
• cargo fmt --all -- --check
• git diff --check

[QuakeWang]

+1