Missing event-cpi fix in v1.1 changelog

[ZdravkoHr]

Description

The v1.1.0 section of CHANGELOG.md appears to omit #4382:

• use UncheckedAccount instead of AccountInfo in #[event_cpi] macro #4382

That PR changed the accounts injected by #[event_cpi] from the
deprecated AccountInfo type to UncheckedAccount. It was merged
and assigned to the v1.1.0 milestone.

Evidence

The released source confirms the behavior change:

• v1.0.2 generates AccountInfo:
  https://github.com/otter-sec/anchor/blob/v1.0.2/lang/syn/src/parser/accounts/event_cpi.rs#L63-L65
• v1.1.2 generates UncheckedAccount:
  https://github.com/otter-sec/anchor/blob/v1.1.2/lang/syn/src/parser/accounts/event_cpi.rs#L63-L65

This is relevant to users upgrading projects that use #[event_cpi]
because the change removes unavoidable deprecation warnings and allows
those projects to compile with warnings denied.

This is separate from #4744, which concerns the website not reflecting
the repository changelog. The entry is absent from the repository
tagged changelog itself.

Suggested entry

Under the v1.1.0 fixes:

* lang/syn: Use `UncheckedAccount` instead of deprecated `AccountInfo`
  for accounts injected by `#[event_cpi]` (#4382).