Update vendored .gitattributes (#12322)

These `linguist-vendored` attributes are only for the language stats
seen on github and they mostly haven't been updated with file
reorganizations. Move them to the two actually vendored directories.

Co-authored-by: techknowlogick <techknowlogick@gitea.io>

.gitattributes

@@ -1,10 +1,3 @@
 * text=auto eol=lf
-/vendor/** -text -eol
+/vendor/** -text -eol linguist-vendored
-/public/vendor/** -text -eol
+/public/vendor/** -text -eol linguist-vendored
-
-conf/* linguist-vendored
-docker/* linguist-vendored
-options/* linguist-vendored
-public/* linguist-vendored
-build/* linguist-vendored
-templates/* linguist-vendored