Always force LF line endings in old test .ok files

Always force LF line endings in old test .ok files

Problem: When running tests on a source tree checked out with git for
Windows, the old tests fail.

The Git for Windows installer installs git with core.autocrlf=true by
default. If you check out, build, and run tests using such a git, the
old test .ok files will likely fail because they use CRLF line endings.
Tests on Windows assume that .ok files use LF line endings, and
appropriately convert the line endings of related files.  This
assumption breaks down when .ok files use CRLF.

Solution: Force LF line endings for old test .ok files in the
.gitattributes file.  Related to that, we've stopped explicitly
specifying line endings when checking out in CI, since this is no longer
necessary.

While at it, also fix a typo in the comment of the gitattributes file.

closes: #19086

Signed-off-by: Muraoka Taro <koron.kaoriya@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>