fix(ci): isolate SPM and DerivedData to prevent cache corruption

- Remove destructive clean step that causes corruption when dirs are in use
- Add -derivedDataPath to isolate CI build from user Xcode cache
- Add -clonedSourcePackagesDirPath to isolate SPM clones
- Fix Package IPA step to use new isolated derived data path

.gitea/workflows/pr-iphone-deploy.yml

@@ -54,7 +54,6 @@ jobs:
       - name: Build app
         run: |
           cd tabatago-swift
-          rm -rf ~/Library/Developer/Xcode/DerivedData ~/Library/Caches/org.swift.swiftpm
           xcodebuild -list
           xcodebuild build \
             -project TabataGo.xcodeproj \
@@ -62,13 +61,16 @@ jobs:
             -destination "generic/platform=iOS" \
             -configuration Debug \
             -allowProvisioningUpdates \
+            -derivedDataPath ../build/derived \
+            -clonedSourcePackagesDirPath ../build/spm-cache \
             -skipPackagePluginValidation \
             CODE_SIGN_STYLE=Automatic DEVELOPMENT_TEAM=2MJF39L8VY SWIFT_ENABLE_EXPLICIT_MODULES=NO
 
       - name: Package IPA
         run: |
+          cd tabatago-swift
           mkdir -p Payload
-          cp -R "$(find build -name '*.app' -type d | head -1)" Payload/
+          cp -R "$(find ../build/derived -name '*.app' -type d | head -1)" Payload/
           zip -r build/TabataGo.ipa Payload/
           rm -rf Payload