patch 8.2.4182: memory leak when evaluating 'diffexpr'

Problem:    Memory leak when evaluating 'diffexpr'.
Solution:   Use free_tv() instead of clear_tv().
diff --git a/src/version.c b/src/version.c
index cc5c101..fcf40bd 100644
--- a/src/version.c
+++ b/src/version.c
@@ -751,6 +751,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    4182,
+/**/
     4181,
 /**/
     4180,