fix: Removed set_status after cancel from Expense Claim and Employee Advance

[pateljannat]

Issue

1. From Expense Claim and Employee Advance, the set_status function is called explicitly.
2. This is not needed as the Status gets updated to Cancelled even without calling these functions on cancel.

[ankush]

Semgrep failure is not false positive, though it may seem so because set_status is also called from validate.

If it's required in on_submit use self.db_set.

[ruchamahabal]

Since set_status is also called on validate when changes are not committed to the db, we can use a flag update=False in the method to understand whether to use db_set or not. Pass True to set_status when called from on_submit. Keep it false by default.

[ruchamahabal]

@pateljannat port this to develop too?