update HISTORY.md and version.h for 6.23.3

Do not attempt to rename non-existent info log (#8622)

Summary:
Previously we attempted to rename "LOG" to "LOG.old.*" without checking
its existence first. "LOG" had no reason to exist in a new DB.

Errors in renaming a non-existent "LOG" were swallowed via
`PermitUncheckedError()` so things worked. However the storage service's
error monitoring was detecting all these benign rename failures. So it
is better to fix it. Also with this PR we can now distinguish rename failure
for other reasons and return them.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8622

Test Plan: new unit test

Reviewed By: akankshamahajan15

Differential Revision: D30115189

Pulled By: ajkr

fbshipit-source-id: e2f337ffb2bd171be0203172abc8e16e7809b170

Mention PR 8585 in HISTORY.md

Bump version number to 6.23.2

Fix NotifyOnFlushCompleted() for atomic flush (#8585)

Summary:
PR https://github.com/facebook/rocksdb/issues/5908 added `flush_jobs_info_` to `FlushJob` to make sure
`OnFlushCompleted()` is called after committing flush results to
MANIFEST. However, `flush_jobs_info_` is not updated in atomic
flush, causing `NotifyOnFlushCompleted()` to skip `OnFlushCompleted()`.

This PR fixes this, in a similar way to https://github.com/facebook/rocksdb/issues/5908 that handles regular flush.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8585

Test Plan: make check

Reviewed By: jay-zhuang

Differential Revision: D29913720

Pulled By: riversand963

fbshipit-source-id: 4ff023c98372fa2c93188d4a5c8a4e9ffa0f4dda

Mention PR 8605 in HISTORY.md (#8619)

Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/8619

Reviewed By: riversand963

Differential Revision: D30081937

Pulled By: ltamasi

fbshipit-source-id: 57505957ae2c22d4b194aa28cb3fd261b3b39919