patch 9.0.0265: no good reason why the "gf" command isn't in the tiny version

Problem:    No good reason why the "gf" command is not in the tiny version.
Solution:   Graduate the file_in_path feature.
diff --git a/runtime/doc/builtin.txt b/runtime/doc/builtin.txt
index 7df5e9f..49d538d 100644
--- a/runtime/doc/builtin.txt
+++ b/runtime/doc/builtin.txt
@@ -2736,8 +2736,6 @@
 		Returns an empty string if the directory is not found.
 
 		This is quite similar to the ex-command `:find`.
-		{only available when compiled with the |+file_in_path|
-		feature}
 
 		Can also be used as a |method|: >
 			GetName()->finddir()
@@ -10532,7 +10530,8 @@
 extra_search		Compiled with support for |'incsearch'| and
 			|'hlsearch'|
 farsi			Support for Farsi was removed |farsi|.
-file_in_path		Compiled with support for |gf| and |<cfile>|
+file_in_path		Compiled with support for |gf| and |<cfile>| (always
+			true)
 filterpipe		When 'shelltemp' is off pipes are used for shell
 			read/write/filter commands
 find_in_path		Compiled with support for include file searches