fix: Exclude DerivedData and SourcePackages from SwiftLint

SwiftLint run script phase in Sentry target was linting SPM checkouts
(DerivedData/SourcePackages/checkouts), causing build failures due to
third-party code violations (e.g. Regex __allTests). Exclude these paths
so SwiftLint only lints project source code.

Author: philprime

.swiftlint.yml

@@ -1,5 +1,7 @@
 excluded:
   - Pods
+  - DerivedData
+  - "**/SourcePackages/**"
   - Utils/**/.build
   - Samples/**/.build
   - "**/build/**"