Remove noisy INFO log in ResetMaxSize and fix hpack UT instability

[wwbmmm]

What problem does this PR solve?

Related to #3473

Problem Summary:

The HPackTest.many_dynamic_table_size_updates test (introduced in
PR #3343) was unstable in clang-unittest-asan CI, frequently hanging.

Root cause:

200000 LOG(INFO) lines in a single test — ResetMaxSize() printed
a LOG(INFO) on every call. The test feeds 200000 consecutive Dynamic
Table Size Update entries, each triggering an INFO log, flooding the
output with 200000+ lines. Under ASAN this log storm was slow enough to
timeout CI jobs.

What is changed and the side effects?

Changed:

• Remove the LOG(INFO) from IndexTable::ResetMaxSize(). This was a
  debug-only log that printed on every HTTP/2 table size update — it had
  no place in production code and was the direct cause of the log storm.

Side effects:

• Performance effects: Removing the LOG(INFO) from ResetMaxSize() is a
  minor improvement for all HTTP/2 decoding paths that handle table size
  updates.
• Breaking backward compatibility: none.

How to test?

• The test case HPackTest.many_dynamic_table_size_updates now runs under
  ASAN in ~1ms with 12 lines of log output (previously ~527ms with
  200012 lines).

Check List:

• Please make sure your changes are compilable.

[Copilot]

Pull request overview

This PR removes a high-volume LOG(INFO) inside HPACK dynamic table size update handling to prevent unit test instability/timeouts (notably under ASAN) caused by excessive log output in tight loops.

Changes:

• Remove the per-call LOG(INFO) from IndexTable::ResetMaxSize() in HPACK decoding.
• Reduce log spam during long sequences of Dynamic Table Size Update entries, improving CI reliability/performance for the related HPACK unit test.

Suppressed comments (1)

src/brpc/details/hpack.cpp:185

• The commented-out LOG/return in this branch is misleading (it calls the new_max_size increase “Invalid” even though the code accepts it) and adds noise in a hot-path method. Please remove the dead commented-out lines to avoid confusion for future readers.

            //LOG(ERROR) << "Invalid new_max_size=" << new_max_size;
            //return -1;
            _max_size = new_max_size;
            return;
        }

---

💡 Add a code-review agent skill or configure MCP servers for context-aware, tailored reviews. Learn more in the docs.

[chenBright]

LGTM