Remove check for final new line

[jcar87]

Have yet to encounter any evidence whatsoever that this check "prevented" us from experiencing any issues.

• All compilers I've tested will accept files that don't end in a newline, even with the most pedantic level of errors and warnings
• Have not found any evidence in Conan Center, for any version, that a compiler ever failed due to lack of blank end of file line - this seems to be more of a theoretical hook
• C++ 11 and onwards does not require it
• Most evidence online of a compiler warning with the text " warning: no newline at end of file." point to gcc 15 years ago or longer

Python, cmake, yaml files do not "require" this - yet to experience any errors

This only adds noise to conan center PRs - and unnecessary failures.