patch 8.2.0288: Vim9: some float and blob operators not tested

Problem:    Vim9: some float and blob operators not tested.
Solution:   Add float and blob tests.  Fix addition.
diff --git a/src/version.c b/src/version.c
index 4be1aa3..39a0fda 100644
--- a/src/version.c
+++ b/src/version.c
@@ -739,6 +739,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    288,
+/**/
     287,
 /**/
     286,