ci: set codecov flags (#5743)

Author: itaybre

.github/workflows/test.yml

@@ -283,3 +283,4 @@ jobs:
           token: ${{ secrets.CODECOV_TOKEN }}
           verbose: true
           name: sentry-cocoa-unit-tests
+          flags: unittests-${{ matrix.platform }}-${{ matrix.xcode }}-${{ matrix.test-destination-os }}

.github/workflows/ui-tests-common.yml

@@ -125,6 +125,7 @@ jobs:
           token: ${{ secrets.CODECOV_TOKEN }}
           verbose: true
           name: sentry-cocoa-unit-tests
+          flags: ui-tests-${{ inputs.fastlane_command }}-${{ inputs.xcode_version }}
 
       - name: Upload Result Bundle
         uses: actions/upload-artifact@v4