fix: don't lint DerivedData and remove force unwrapping

[cbaker6]

New Pull Request Checklist

• I am not disclosing a vulnerability.
• I am creating this PR in reference to an issue.

Issue Description

In latest version of Xcode, the linter sometimes tries to lint dummy files added by Xcode in the DerivedData folder, causing errors.

Related issue: #n/a

Approach

Make SwiftLint ignore the DerivedData folder.

TODOs before merging

• Use optional binding instead of force unwrapping

[parse-github-assistant]

Thanks for opening this pull request!

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[codecov]

Codecov Report

Merging #304 (8761ea3) into main (931ae8f) will decrease coverage by 0.03%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##             main     #304      +/-   ##
==========================================
- Coverage   83.73%   83.70%   -0.04%     
==========================================
  Files         105      105              
  Lines       11154    11154              
==========================================
- Hits         9340     9336       -4     
- Misses       1814     1818       +4     

Impacted Files	Coverage Δ
Sources/ParseSwift/Types/QueryWhere.swift	100.00% <100.00%> (ø)
Sources/ParseSwift/LiveQuery/ParseLiveQuery.swift	72.92% <0.00%> (-0.60%)	⬇️

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