Isoweek bug when customParseFormat is active

**Describe the bug**
When I try to get the iso week number from a date, the isoWeek function is not correct.

**Information**
Bug has been reproduced in this [sandbox](https://codesandbox.io/p/sandbox/dayjs-isoweek-and-customparseformat-bug-t4xg37)

We get a very incoherent value :
- `dayjs.utc("2024-01-16T22:00:00.000Z").locale("fr").tz("Europe/Paris").isoWeek()` return 3
- `dayjs.utc("2024-01-16T23:00:00.000Z").locale("fr").tz("Europe/Paris").isoWeek()` return 2

That makes no sense, if A > B then A.isoWeek() >= B.isoWeek()

I don't really understand what is happening.

My guess is that when time is 23-23h59, the timezone makes the day change from 16 to 17 according to TZ. This day change leads to a decremented isoWeek.

I have tried to remove `customParseFormat` from used plugin and it started working. You can try it on the sandbox. However I need this plugin to make parse date in my TZ.

Thanks for your help.

Start by running the linked CodeSandbox with customParseFormat, utc, timezone, and isoWeek enabled, then compare the two timestamps and plugin interactions. Trace how the plugins parse and convert the date before isoWeek() calculates the result. Done means the reported timestamps produce consistent ISO week values and a regression test covers the case.

Written by the indexing model from the issue text.