build(deps): bump libmozdata from 0.1.70 to 0.1.72 in /bot

Bumps [libmozdata](https://github.com/mozilla/libmozdata) from 0.1.70 to 0.1.72.
- [Release notes](https://github.com/mozilla/libmozdata/releases)
- [Commits](mozilla/libmozdata@v0.1.70...v0.1.72)

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

Author: dependabot[bot]

bot/requirements.txt

@@ -1,6 +1,6 @@
 -e ../tools #egg=code-coverage-tools
 google-cloud-storage==1.38.0
-libmozdata==0.1.70
+libmozdata==0.1.72
 pytoml==0.1.21
 pytz==2021.1
 pyyaml==5.4.1