Bump minimum needed R version to 4.0

[IndrajeetPatil]

Closes #1196

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 50.00000% with 1 lines in your changes are missing coverage. Please review.

Project coverage is 92.17%. Comparing base (775c399) to head (1a3ef50). Report is 22 commits behind head on main.

:exclamation: Current head 1a3ef50 differs from pull request most recent head ed8b058. Consider uploading reports for the commit ed8b058 to get more accurate results

Files	Patch %	Lines
R/environments.R	0.00%	1 Missing :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #1197 +/- ## ======================================= Coverage 92.16% 92.17% ======================================= Files 46 46 Lines 2654 2657 +3 ======================================= + Hits 2446 2449 +3 Misses 208 208 ```

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[github-actions[bot]]

This is how benchmark results would change (along with a 95% confidence interval in relative change) if f5744da371242da992fff46b35253aa80cba6844 is merged into main:

• :heavy_check_mark:cache_applying: 158ms -> 156ms [-4.19%, +1.21%]
• :heavy_check_mark:cache_recording: 520ms -> 521ms [-1.01%, +1.08%]
• :heavy_check_mark:without_cache: 989ms -> 986ms [-0.99%, +0.34%]

Further explanation regarding interpretation and methodology can be found in the documentation.

[lorenzwalthert]

You are currently a contributor of the package and you contribute a lot. Thank you for that. I think the amount and quality would qualify you to be an author. Would you be interested?

[IndrajeetPatil]

I would be honored to! Thanks 💕