patch 9.1.1304: filetype: some man files are not recognized

Problem:  filetype: some man files are not recognized
          (e.g. 1p (POSIX commands))
Solution: update the filetype detection pattern and detect more man
          files as nroff (Eisuke Kawashima)

- sections are revised referring to
    - debian-12:/etc/manpath.config
    - fedora-41:/etc/man_db.conf
- detection logic is improved
- detection test is implemented

closes: #17117

Signed-off-by: Eisuke Kawashima <e-kwsm@users.noreply.github.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/version.c b/src/version.c
index e2314ca..30904d7 100644
--- a/src/version.c
+++ b/src/version.c
@@ -705,6 +705,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1304,
+/**/
     1303,
 /**/
     1302,