docs: matplotlib: update for 3.11.0

Signed-off-by: Trevor Gamblin <tgamblin@baylibre.com>

Author: threexc

docs/packages/matplotlib.yaml

@@ -13,3 +13,6 @@ versions:
   - version: 3.10.7
   - version: 3.10.8
   - version: 3.10.9
+  - version: 3.11.0
+    patched:
+    comment: We patch matplotlib to increase threading test timeouts in places where the native RISC-V runners seem to have issues, and backport a fix from upstream to pin pytest below version 9.1.0 due to failures with a test fixture in the TestSpectral suite.