Valid date with UTC offset fails validaton

**Describe the bug**

1. Using the following date as an example:
`var input = "09/04/2024 21:12:50 +00:00";`
2. Strictly validate the input:
`var isValidDayJsDate = dayjs(input, "MM/DD/YYYY HH:mm:ss Z", true).isValid();`
3. BUG: Validation fails.

**Expected behavior**

Compliant date should pass validation.

**Information**
- Day.js Version 1.11.11
- OS: Windows 11 Pro
- Browser chrome 128
- Time zone: [e.g. GMT-07:00 DST (Pacific Daylight Time)]

Start by reproducing the strict parsing call with the supplied date, format, and Day.js version, then trace the custom-format parsing path that handles the UTC offset token. Done means the compliant input returns true from isValid() without breaking other strict date validations.

Written by the indexing model from the issue text.