merge revision(s) d8ef0a98c670449b20436947f5ebbd327ed5ab0d: [Backport #19319]

	[Bug #19319] Fix crash in rb_str_casemap

	The following code crashes on my machine:

	```
	GC.stress = true

	str = "testing testing testing"

	puts str.capitalize
	```

	We need to ensure that the object `buffer_anchor` remains on the stack
	so it does not get GC'd.
	---
	 string.c | 2 ++
	 1 file changed, 2 insertions(+)

1 files changed, 1 insertions, 1 deletions

diff --git a/version.h b/version.h
index 0dc0c87858..fb6cd1f326 100644
--- a/version.h
+++ b/version.h
@@ -11,7 +11,7 @@
 # define RUBY_VERSION_MINOR RUBY_API_VERSION_MINOR
 #define RUBY_VERSION_TEENY 4
 #define RUBY_RELEASE_DATE RUBY_RELEASE_YEAR_STR"-"RUBY_RELEASE_MONTH_STR"-"RUBY_RELEASE_DAY_STR
-#define RUBY_PATCHLEVEL 195
+#define RUBY_PATCHLEVEL 196
 
 #define RUBY_RELEASE_YEAR 2023
 #define RUBY_RELEASE_MONTH 3