[CON-89] Increase tm event buffer to reduce critical path backpressure

[udpatil]

Describe your changes and provide context

Currently, the buffer for tendermint events is too small to properly handle large amounts of traffic, since filling the buffer up will slow down the critical path for execution, resulting in potentially longer block times or at least node falling behind.

Testing performed to validate your change

Tested in loadtest cluster and detacehd pacific-1 RPC

[github-actions]

The latest Buf updates on your PR. Results from workflow Buf / buf (pull_request).

Build	Format	Lint	Breaking	Updated (UTC)
✅ passed	✅ passed	✅ passed	✅ passed	Oct 1, 2025, 9:40 PM

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 57.08%. Comparing base (c6c5a8f) to head (3f4d454).

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #329      +/-   ##
==========================================
+ Coverage   56.94%   57.08%   +0.13%     
==========================================
  Files         254      254              
  Lines       33815    33815              
==========================================
+ Hits        19257    19302      +45     
+ Misses      13017    12968      -49     
- Partials     1541     1545       +4     

Files with missing lines	Coverage Δ
internal/eventbus/event_bus.go	89.18% <ø> (ø)

... and 11 files with indirect coverage changes

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[yzang2019]

Shall we make it confgurable?