Avoid errors due to log message formatting

[brandonpayton]

Motivation for the change, related issues

Today, we attempt to reassign an error's message property for formatting purposes, but this throws an exception if the error property isn't writable or doesn't have a setter. For example:

TypeError: Cannot set property message of #<ErrorEvent2> which has only a getter

These are the assignments that occasionally lead to the error:
https://github.com/WordPress/wordpress-playground/blob/trunk/packages/php-wasm/logger/src/lib/handlers/log-to-console.ts#L9-L11

Since the assignments are just for formatting, it should be OK if we just tolerate the failed assignment using Reflect.set().

Fixes #1514

Implementation details

Use Reflect.set() to avoid exceptions when the assignment fails.

Testing Instructions (or ideally a Blueprint)

• CI
• Tested manually by causing errors in the PHP runtime