add callout for SPEC-0

Author: JostMigenda

episodes/optimisation-use-latest.md

@@ -36,6 +36,16 @@ These improvements are often free, requiring minimal changes to any code (unlike
 
 Performance regressions within major packages should be considered rare, they often track performance alongside their test suites.
 
+::::::::::::::::::::::::::::::::::::: callout
+
+## Support for older Python versions in the Scientific Python ecosystem
+
+In the last few years, many important packages in the Scientific Python ecosystem have agreed [a common policy](https://scientific-python.org/specs/spec-0000/) to support previous versions of Python for 3 years.
+For example, since October 2024, these packages stopped supporting Python 3.10; so if you are still using Python 3.10 (or even older versions), you’re now losing access to new features and performance improvements in NumPy, SciPy, Matplotlib and many other libraries. Time to update!
+
+:::::::::::::::::::::::::::::::::::::
+
+
 <!-- Not always possible due to incompatibilities -->
 However, the more packages and language features your code touches, and the older the Python it currently uses, the greater chance of incompatibilities making it difficult to upgrade.