Log formatting of classes/types is broken

[thevintik]

Describe the incorrect behavior you saw
Attempt to write type in log fails.

Describe how to cause this behavior
Emit log message that implies some type formatting.

>>> from twisted.logger import eventAsText
>>> eventAsText({"log_format": "{value}", "value": RuntimeError})
"- [-#-] Unable to format event {'log_format': '{value}', 'value': <class 'RuntimeError'>}: object.__format__() takes exactly one argument (0 given)"

Describe the correct behavior you'd like to see
Type is being formatted just like in format() call.

Additional context
The regression was introduced in Twisted 24.3.0 (#12040)
23.10.0 works fine:

>>> from twisted.logger import eventAsText
>>> eventAsText({"log_format": "{value}", "value": RuntimeError})
"- [-#-] <class 'RuntimeError'>"