Add blurb

Author: mdboom

Misc/NEWS.d/next/C_API/2025-03-20-17-14-29.gh-issue-131525.n8Di6a.rst

@@ -0,0 +1,7 @@
+The PyTupleObject now caches the computed hash value in the new field
+ob_hash.
+
+# Write your Misc/NEWS.d entry below.  It should be a simple ReST paragraph.
+# Don't start with "- Issue #<n>: " or "- gh-issue-<n>: " or that sort of
+stuff.
+###########################################################################