revert: rollback AHashMap changes and keep using std HashMap (#6741)

* Revert "perf(ecstore): use AHashMap for FileInfo metadata fields (#6738)"

This reverts commit 13a2ae212e.

* fix(filemeta): restore standard HashMap metadata (#6742)

Remove the direct ahash dependency added for FileInfo metadata and revert the affected filemeta/ecstore call sites back to std::collections::HashMap.

Co-authored-by: heihutu <heihutu@gmail.com>

---------

Co-authored-by: heihutu <heihutu@gmail.com>

crates/ecstore/Cargo.toml

@@ -218,9 +218,6 @@ faster-hex = { workspace = true }
 ratelimit = { workspace = true }
 aws-smithy-http-client = { workspace = true, default-features = false, features = ["rustls-aws-lc"] }
 
-# High-performance hashing
-ahash = { workspace = true, features = ["serde"] }
-
 # Observability and Metrics
 metrics = { workspace = true }