patch 9.1.1080: filetype: Mill files are not recognized

Problem:  filetype: Mill files are not recognized
Solution: detect '*.mill' files as scala filetype
          (author)

In the past [Mill](https://mill-build.org/mill/index.html) build files
were always `build.sc` and treated as Scala files. However as the 0.12.x
series of mill you can create a `build.mill` file. You can see a lot of
examples of this if you search
[GitHub](https://github.com/search?q=build.mill&type=code). This small
change just ensures that if you have a `*.mill` file it treats it as a
Scala file.

closes: #16585

Signed-off-by: Chris Kipp <ckipp@pm.me>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/version.c b/src/version.c
index 8fc6f60..d8e8c0e 100644
--- a/src/version.c
+++ b/src/version.c
@@ -705,6 +705,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1080,
+/**/
     1079,
 /**/
     1078,