Fix MyPy CI tests

[karthiknadig]

For #8517

• Pull request represents a single change (i.e. not fixing disparate/unrelated things in a single PR)
• Title summarizes what is changing
• Unit tests & system/integration tests are added/updated

[codecov-io]

Codecov Report

Merging #8518 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master    #8518   +/-   ##
=======================================
  Coverage   59.11%   59.11%           
=======================================
  Files         510      510           
  Lines       23564    23564           
  Branches     3813     3813           
=======================================
  Hits        13931    13931           
  Misses       8725     8725           
  Partials      908      908

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 1b6fbfb...2180bc1. Read the comment docs.