Use strict types with PluginDriver

[NotWoods]

This PR contains:

• bugfix
• feature
• refactor
• documentation
• other

Are tests included?

• yes (bugfixes and features will not be merged without tests)
• no

Breaking Changes?

• yes (breaking changes will not be merged unless absolutely necessary)
• no

List any relevant issue numbers:

Description

Adds strict typing for the PluginDriver class.

[codecov]

Codecov Report

Merging #3426 into master will increase coverage by 0.00%.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##           master    #3426   +/-   ##
=======================================
  Coverage   95.00%   95.01%           
=======================================
  Files         171      171           
  Lines        5831     5834    +3     
  Branches     1722     1722           
=======================================
+ Hits         5540     5543    +3     
  Misses        157      157           
  Partials      134      134           

Impacted Files	Coverage Δ
src/utils/renderChunk.ts	100.00% <ø> (ø)
src/utils/transform.ts	98.43% <ø> (ø)
src/ast/nodes/MetaProperty.ts	100.00% <100.00%> (ø)
src/rollup/rollup.ts	100.00% <100.00%> (ø)
src/utils/PluginDriver.ts	100.00% <100.00%> (ø)

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[lukastaegert]

Nice work! There were small remaining type errors in the code which were picked up by CI. You can also run this check manually via npm run test:typescript. Luckily, they were easy to fix so I took the liberty of pushing the fix to your branch.