chore: bump iceberg-rust to 20260807 baseline

[chenzl25]

Summary

• bump all iceberg-rust dependencies to the finalized dev_rebase_main_20260807 head at aac27678a717deef473e98b026ce54dbf8a4670b
• include the merged Glue timestamp mapping and factory-scoped OpenDAL operator cache fixes
• adapt compaction and DataFusion scan code to the current iceberg-rust scan, object-cache, delete-file, and storage-factory APIs
• preserve position/equality delete handling, including distinct Puffin blob ranges
• align DataFusion/Arrow and the Rust toolchain with the new iceberg-rust baseline

Dependency chain

• upstream dependency branch: https://github.com/risingwavelabs/iceberg-rust/tree/dev_rebase_main_20260807
• upstream tracking issue: [Rebase Tracking] Build dev_rebase_main_20260807 from latest apache/main risingwavelabs/iceberg-rust#191
• downstream RisingWave PR: feat(iceberg): bump iceberg-rust dependencies to 20260807 baseline risingwavelabs/risingwave#26619

Validation

• cargo check --locked --workspace --all-targets --all-features
• make check (rustfmt, Clippy with -D warnings, Taplo)
• make unit-test (135 passed)
• GitHub CI: Check, Build, Unit Test, and Integration Test all passed