[3.10] bpo-45335: Add note to sqlite3 docs about "timestamp" converter (GH-29200)

[miss-islington]

(cherry picked from commit 3877fc0)

Co-authored-by: Ian Fisher ian@iafisher.com

https://bugs.python.org/issue45335

[miss-islington]

@iafisher and @ambv: Status check is done, and it's a failure ❌ .

[miss-islington]

@iafisher and @ambv: Status check is done, and it's a failure ❌ .

[miss-islington]

@iafisher and @ambv: Status check is done, and it's a failure ❌ .

[miss-islington]

@iafisher and @ambv: Status check is done, and it's a success ✅ .