Patch packaging's pyparsing dependency

[jakirkham]

This needs to have an upper bound of 3, but was missed updating.

From show_diff.py:

noarch::packaging-21.2-pyhd8ed1ab_0.tar.bz2
-    "pyparsing >=2.0.2",
+    "pyparsing >=2.0.2,<3",

xref: conda-forge/packaging-feedstock#21

cc @conda-forge/packaging @krassowski

---

Checklist

• Used a personal fork of the feedstock to propose changes
• Bumped the build number (if the version is unchanged)
• Reset the build number to 0 (if the version changed)
• Re-rendered with the latest conda-smithy (Use the phrase @conda-forge-admin, please rerender in a comment in this PR for automated rerendering)
• Ensured the license file is being packaged.

[conda-forge-linter]

Hi! This is the friendly automated conda-forge-linting service.

I just wanted to let you know that I linted all conda-recipes in your PR (recipe) and found it was in an excellent condition.

[github-actions]

Hi! This is the friendly conda-forge automerge bot!

I considered the following status checks when analyzing this PR:

• linter: passed
• azure: passed

Thus the PR was passing and merged! Have a great day!