Bump libevent to 2.1.12

What does this MR do?

Bump libevent to 2.1.12

- Update libevent from 2.1.8 to 2.1.12

Related https://gitlab.com/gitlab-org/omnibus-gitlab/-/issues/7839

Signed-off-by: Robert Marshall <rmarshall@gitlab.com>

Discovered problems building libevent while testing Add Debian 12 builder images (gitlab-omnibus-builder!288 - merged)

From the test build pipeline:

/usr/bin/ld: ./.libs/libevent.so: undefined reference to `arc4random_addrandom'
/usr/bin/ld: ./.libs/libevent_core.so: undefined reference to `arc4random_addrandom'
/usr/bin/ld: ./.libs/libevent.so: undefined reference to `arc4random_addrandom'

In the CHANGELOG from libevent version 2.1.9-beta:

Fix arc4random_addrandom() detecting and fallback (regression) (303d6d77g)

Verified that 2.1.9-beta resolves the build issues.

Executed a build with 2.1.12-stable and installed the Debian 12 package to validate it works.

The full 2.1.2-stable CHANGELOG.

Notable changes:

• 2.1.11-stable
  • ABI breakage:
    • Protect min_heap_push_ against integer overflow. (8c899768 Tobias Stoeckmann)
    • Revert "Protect min_heap_push_ against integer overflow." (18104973 Azat Khuzhin)

This is the issue upstream that tracked the fix in 2.1.9-beta.

Related issues

Related #7839 (closed)

Checklist

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