patch 9.1.0897: filetype: pyrex files are not detected

Problem:  filetype: pyrex files are not detected
Solution: detect '*.pxi' and '*.pyx+' as pyrex filetype
          (user202729)

References:
https://cython.readthedocs.io/en/latest/src/userguide/language_basics.html#cython-file-types
https://www.csse.canterbury.ac.nz/greg.ewing/python/Pyrex/version/Doc/Manual/using_with_c++.html

closes: #16136

Signed-off-by: user202729 <25191436+user202729@users.noreply.github.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/testdir/test_filetype.vim b/src/testdir/test_filetype.vim
index 4a905a8..51f4dc1 100644
--- a/src/testdir/test_filetype.vim
+++ b/src/testdir/test_filetype.vim
@@ -613,7 +613,7 @@
     purescript: ['file.purs'],
     pymanifest: ['MANIFEST.in'],
     pyret: ['file.arr'],
-    pyrex: ['file.pyx', 'file.pxd'],
+    pyrex: ['file.pyx', 'file.pxd', 'file.pxi', 'file.pyx+'],
     python: ['file.py', 'file.pyw', '.pythonstartup', '.pythonrc', '.python_history', '.jline-jython.history', 'file.ptl', 'file.pyi', 'SConstruct'],
     ql: ['file.ql', 'file.qll'],
     qml: ['file.qml', 'file.qbs'],
diff --git a/src/version.c b/src/version.c
index e1f8489..e3093a3 100644
--- a/src/version.c
+++ b/src/version.c
@@ -705,6 +705,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    897,
+/**/
     896,
 /**/
     895,