feat: Add incremental caching for Rust CI builds
Enable incrementalTasks future flag and add incremental partitions to
the cli build and build:test-archive tasks. Cargo intermediate artifacts
(deps, fingerprints, build script outputs) are cached via the remote
cache, excluding .rlib files to keep upload size manageable.
Also fixes the incremental partition key to incorporate the task hash,
ensuring partitions inherit all task-level configuration (globalEnv,
env, etc.) and are properly segmented across platforms.
Moves the 'incremental' suffix from prepend to append in the partition
key format.
