E703: Incorrect detection and replacement of semicolon

[addisoncrump]

Okay, I'll be the first to say it, but this bug is really not that important. I'm reporting it primarily because it implies that there may be other issues with semicolon/newline processing in other situations I haven't observed yet.

The following snippet is a valid Python script (no trailing newline):

0\
;

Ruff attempts to correct it to the following (with trailing newline, but it's escaped):

0\

As a result, there is an EOF syntax error. This only applies to a situation where a) there is a semicolon at the end of the input (no trailing newline), and b) the line before is escaped.

Discovered with #4822.