fix: Add graceful fail if MSC4140 event delay exceeded

[jasonlaguidice]

Description

No one has complained about this yet but this adds graceful failure if the server's max event delay for MSC4140 delayed messages is exceeded.

There, sadly, is no method for the server to advertise it's current max allowable event delay without just trying a time that's too long.

Fixes N/A

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings