build(deps): bump pyparsing from 3.1.1 to 3.1.2

Bumps [pyparsing](https://github.com/pyparsing/pyparsing) from 3.1.1 to 3.1.2.
- [Release notes](https://github.com/pyparsing/pyparsing/releases)
- [Changelog](https://github.com/pyparsing/pyparsing/blob/master/CHANGES)
- [Commits](pyparsing/pyparsing@3.1.1...pyparsing_3.1.2)

---
updated-dependencies:
- dependency-name: pyparsing
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>

requirements/optional.txt

@@ -18,7 +18,7 @@ mistletoe==1.3.0       # Markdown
 phply==1.2.6         # PHP
 pyenchant==3.2.2     # spellcheck
 # Windows Resources (rc2po and po2rc)
-pyparsing==3.1.1     # RC
+pyparsing==3.1.2     # RC
 # Faster matching in e.g. pot2po
 python-Levenshtein>=0.12    # Levenshtein
 # Format support