Update the example digest for the fixes on develop

The eight commits merged from develop change the library and
periodic_3D.xml, so the figures the examples produce are no longer the
ones in the published archive. The digest check caught it, which is what
it is for:

    EXAMPLES_DIGEST is 314fadcaec7cb6e5, the examples digest to
    2d39355b71ddd257.

The documentation workflow publishes an archive for the new digest and
asks Read the Docs to build again with it.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

Author: kip-hart

docs/source/sphinx_gallery/plot_demos.py

@@ -24,7 +24,7 @@
 # them is edited, and the build would serve stale figures.
 #
 # Managed by docs/example_digest.py. Do not edit by hand.
-EXAMPLES_DIGEST = '314fadcaec7cb6e5'
+EXAMPLES_DIGEST = '2d39355b71ddd257'
 
 example_dir = '../../../src/microstructpy/examples'