Make transform_signature_to_interface compatible with 3.9 NamedTuple

[fediazgon]

TL;DR

Make transform_signature_to_interface compatible with 3.9 NamedTuple

Type

• Bug Fix
• Feature
• Plugin

Are all requirements met?

• Code completed
• Smoke tested
• Unit tests added
• Code documentation added
• Any pending items have an associated Issue

Complete description

Similar to https://github.com/flyteorg/flytekit/pull/471/files

Tracking Issue

flyteorg/flyte#1166

[codecov]

Codecov Report

Merging #534 (21190b6) into master (2c9fab4) will increase coverage by 0.00%.
The diff coverage is 85.71%.

@@           Coverage Diff           @@
##           master     #534   +/-   ##
=======================================
  Coverage   85.40%   85.40%           
=======================================
  Files         371      371           
  Lines       28473    28476    +3     
  Branches     2304     2305    +1     
=======================================
+ Hits        24318    24321    +3     
  Misses       3523     3523           
  Partials      632      632           

Impacted Files	Coverage Δ
flytekit/core/interface.py	79.42% <83.33%> (+0.35%)	⬆️
flytekit/core/type_engine.py	85.99% <100.00%> (ø)

---

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 2c9fab4...21190b6. Read the comment docs.