Remove prometheus dependency and metrics (#769)

## Summary
- Remove the `prometheus` crate dependency from the workspace and
`xet_data`
- Delete `prometheus_metrics.rs` which defined 3 IntCounter metrics (CAS
bytes produced, bytes cleaned, bytes smudged)
- Remove metric increment calls from `file_upload_session.rs` and
`file_download_session.rs`
- Fix Windows CI flake: redb "Database already open" error in
`test_single_large`

These metrics were collected but never exposed via any HTTP endpoint or
text encoder, making them effectively dead code.

## Test plan
- [x] `cargo +nightly fmt` — clean
- [x] `cargo clippy --all-targets` — no new warnings
- [x] `cargo test -p xet-data` — 17/17 pass
- [x] `cargo test -p xet-data --features simulation --test
test_clean_smudge` — 14/14 pass (including `test_single_large`)
- [x] WASM builds (`hf_xet_wasm`, `hf_xet_thin_wasm`) — both succeed

<!-- CURSOR_SUMMARY -->
---

> [!NOTE]
> **Low Risk**
> Low risk: this removes unused Prometheus metrics plumbing and related
dependencies without changing the core upload/download logic. Main risk
is loss of any downstream reliance on these counters at build time
(e.g., feature flags or imports).
> 
> **Overview**
> Removes the `prometheus` dependency from the workspace and `xet_data`,
and updates lockfiles accordingly (including WASM-related lockfiles).
> 
> Deletes `xet_data`’s `prometheus_metrics` module and strips the
associated counter increments from `FileUploadSession` and
`FileDownloadSession`, leaving the data processing behavior unchanged
aside from no longer recording these metrics.
> 
> <sup>Written by [Cursor
Bugbot](https://cursor.com/dashboard?tab=bugbot) for commit
c6c866b. This will update automatically
on new commits. Configure
[here](https://cursor.com/dashboard?tab=bugbot).</sup>
<!-- /CURSOR_SUMMARY -->

Author: assafvayner

Cargo.lock

@@ -78,7 +78,6 @@ more-asserts = "0.3"
 oneshot = "0.1"
 pin-project = "1"
 pyo3 = { version = "0.26", features = ["abi3-py37", "multiple-pymethods"] }
-prometheus = "0.14"
 rand = "0.9"
 rand_chacha = "0.9"
 regex = "1"

Cargo.toml

@@ -26,7 +26,6 @@ http = { workspace = true }
 itertools = { workspace = true }
 lazy_static = { workspace = true }
 more-asserts = { workspace = true }
-prometheus = { workspace = true }
 rand = { workspace = true }
 serde = { workspace = true }
 serde_json = { workspace = true }

hf_xet/Cargo.lock

@@ -13,9 +13,9 @@ use xet_client::cas_types::FileRange;
 use xet_client::chunk_cache::ChunkCache;
 use xet_runtime::core::{XetRuntime, xet_config};
 
+use super::XetFileInfo;
 use super::configurations::TranslatorConfig;
 use super::remote_client_interface::create_remote_client;
-use super::{XetFileInfo, prometheus_metrics};
 use crate::error::{DataError, Result};
 use crate::file_reconstruction::{DownloadStream, FileReconstructor, UnorderedDownloadStream};
 use crate::progress_tracking::{GroupProgress, ItemProgressUpdater, UniqueID};
@@ -143,7 +143,6 @@ impl FileDownloadSession {
                 actual: n_bytes,
             });
         }
-        prometheus_metrics::FILTER_BYTES_SMUDGED.inc_by(n_bytes);
         Ok(n_bytes)
     }
 
@@ -189,7 +188,6 @@ impl FileDownloadSession {
             });
         }
 
-        prometheus_metrics::FILTER_BYTES_SMUDGED.inc_by(n_bytes);
         Ok((id, n_bytes))
     }
 

wasm/hf_xet_thin_wasm/Cargo.lock

@@ -17,11 +17,11 @@ use xet_core_structures::metadata_shard::file_structs::MDBFileInfo;
 use xet_core_structures::xorb_object::SerializedXorbObject;
 use xet_runtime::core::{XetRuntime, xet_config};
 
+use super::XetFileInfo;
 use super::configurations::TranslatorConfig;
 use super::file_cleaner::{Sha256Policy, SingleFileCleaner};
 use super::remote_client_interface::create_remote_client;
 use super::shard_interface::SessionShardInterface;
-use super::{XetFileInfo, prometheus_metrics};
 use crate::deduplication::constants::{
     MAX_XORB_BYTES, MAX_XORB_CHUNKS, XORB_CUT_THRESHOLD_BYTES, XORB_CUT_THRESHOLD_CHUNKS,
 };
@@ -503,10 +503,6 @@ impl FileUploadSession {
         metrics.shard_bytes_uploaded = self.shard_interface.upload_and_register_session_shards().await?;
         metrics.total_bytes_uploaded = metrics.shard_bytes_uploaded + metrics.xorb_bytes_uploaded;
 
-        // Update the global counters
-        prometheus_metrics::FILTER_CAS_BYTES_PRODUCED.inc_by(metrics.new_bytes);
-        prometheus_metrics::FILTER_BYTES_CLEANED.inc_by(metrics.total_bytes);
-
         #[cfg(debug_assertions)]
         {
             self.completion_tracker.assert_complete();

wasm/hf_xet_wasm/Cargo.lock

@@ -5,7 +5,6 @@ mod file_cleaner;
 mod file_download_session;
 mod file_upload_session;
 pub mod migration_tool;
-mod prometheus_metrics;
 mod remote_client_interface;
 mod sha256;
 mod shard_interface;