fix(sdk): Disable OrderTracker for the moment

[Hywan]

This patch removes the use of OrderTracker because the implementation of EventCacheStore::load_all_chunks_metadata for SqliteEventCacheStore is the cause of severe slowness (up to 100s for some accounts). It's been introduced in #5225.

We are going to undo this patch once the problem has been solved.
Edit:

• the fix, feat(sqlite): Improve throughput of SqliteEventCacheStore::load_all_chunks_metadata by 1140% #5411
• the undo, Revert "fix(sdk): Disable OrderTracker for the moment." #5412

Metrics

Using this rageshake, the logs introduced in this PR, and this command-line to only list executions of load_all_chunks_metadata taking more than one second:

$ rg '_method_ finished in.*> load_all_chunks_metadata' foo.log | rg '\d+(\.\d+)?s' --only-matching | sort --numeric-sort --reverse
107.121747125s
79.909931458s
10.348993583s
8.827636417s
8.614481625s
8.009787875s
5.99637875s
4.118492334s
3.910040333s
3.718858334s
3.689340667s
3.661383208s
2.310609666s
2.221779s
2.087249333s
1.898318333s
1.320944334s
1.005408875s

[codecov]

Codecov Report

Attention: Patch coverage is 90.00000% with 2 lines in your changes missing coverage. Please review.

Project coverage is 88.84%. Comparing base (7d9d5bf) to head (6bbea2c).
Report is 5 commits behind head on main.

✅ All tests successful. No failed tests found.

Files with missing lines	Patch %	Lines
crates/matrix-sdk/src/event_cache/room/mod.rs	80.00%	0 Missing and 2 partials ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #5407      +/-   ##
==========================================
+ Coverage   88.80%   88.84%   +0.03%     
==========================================
  Files         334      334              
  Lines       91256    91015     -241     
  Branches    91256    91015     -241     
==========================================
- Hits        81044    80862     -182     
+ Misses       6399     6340      -59     
  Partials     3813     3813              

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[poljar]

Alright, let's see if this is actually the culprit.

[Hywan]

For the record, perf is no longer a problem. It confirms this is the culprit. Now let's fix that.