patch 9.1.0548: it's not possible to get a unique id for some vars

Problem:  it's not possible to get a unique id for some vars
Solution: Add the id() Vim script function, which returns a unique
          identifier for object, dict, list, job, blob or channel
          variables (Ernie Rael)

fixes: #14374
closes: #15145

Signed-off-by: Ernie Rael <errael@raelity.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/version.c b/src/version.c
index ce6b8d6..1f334ca 100644
--- a/src/version.c
+++ b/src/version.c
@@ -705,6 +705,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    548,
+/**/
     547,
 /**/
     546,