Update instructions for updating pyodide (#10701)

Author: shoyer

HOW_TO_RELEASE.md

@@ -111,11 +111,11 @@ upstream        https://github.com/pydata/xarray (push)
 
 13. Update the version available on pyodide:
     - Open the PyPI page for [Xarray downloads](https://pypi.org/project/xarray/#files)
-    - Edit [`pyodide/packages/xarray/meta.yaml`](https://github.com/pyodide/pyodide/blob/main/packages/xarray/meta.yaml) to update the
+    - Edit [`packages/xarray/meta.yaml`](https://github.com/pyodide/pyodide-recipes/blob/main/packages/xarray/meta.yaml) to update the
       - version number
       - link to the wheel (under "Built Distribution" on the PyPI page)
       - SHA256 hash (Click "Show Hashes" next to the link to the wheel)
-    - Open a pull request to pyodide
+    - Open a pull request to pyodide-recipes
 
 14. Issue the release announcement to mailing lists & Twitter (X). For bug fix releases, I
     usually only email [email protected]. For major/feature releases, I will email a broader