bump pyodide version number (#735)

Pyodide packages needed rebuilding, and the pyodide project has
moved on a bit so a new version number is needed. The new packages
have already been built and pushed to S3.

To verify, go to `sandbox/pyodide` and follow the README there.
Then at top level do `GRIST_SANDBOX_FLAVOR=pyodide`. Try to
create and edit a document using formulas. It should work.

sandbox/pyodide/Makefile

@@ -1,6 +1,6 @@
 # This number should be bumped up if making a non-additive change
 # to python packages.
-GRIST_PYODIDE_VERSION = 2
+GRIST_PYODIDE_VERSION = 3
 
 default:
 	echo "Welcome to the pyodide sandbox"

sandbox/pyodide/package_filenames.json

@@ -1,6 +1,6 @@
 [
   "astroid-2.14.2-cp311-none-any.whl",
-  "asttokens-2.2.1-cp311-none-any.whl",
+  "asttokens-2.4.0-cp311-none-any.whl",
   "chardet-5.1.0-cp311-none-any.whl",
   "et_xmlfile-1.0.1-cp311-none-any.whl",
   "executing-1.1.1-cp311-none-any.whl",