Refactor FXIOS-12796 [Swift 6 Migration] Fix SiteImageModel warnings (#30376)

* Fix some current build warnings related to strict concurrency.

* Lower warning threshold.

Author: ih-codes

BrowserKit/Sources/SiteImageView/Entities/SiteImageModel.swift

@@ -5,7 +5,7 @@
 import UIKit
 
 /// Stores information related to an image request inside SiteImageView.
-public struct SiteImageModel {
+public struct SiteImageModel: Sendable {
     // A unique ID to tie the request to a certain image view
     let id: UUID
 
@@ -18,8 +18,9 @@ public struct SiteImageModel {
     // Used to cache any resources related to this request
     let cacheKey: String
 
-    // The bundled resource or remote URL (e.g. faviconURL, preferrably high resolution) for this image.
-    var siteResource: SiteResource?
+    // The bundled resource or remote URL (e.g. faviconURL, preferably high resolution) for this image.
+    // FIXME: FXIOS-14017 This property prevents SiteImageModel from being truly Sendable
+    nonisolated(unsafe) var siteResource: SiteResource?
 
     public init(id: UUID,
                 imageType: SiteImageType,

BrowserKit/Sources/SiteImageView/SiteImageHandler.swift

@@ -4,7 +4,7 @@
 
 import UIKit
 
-public protocol SiteImageHandler {
+public protocol SiteImageHandler: Sendable {
     func getImage(model: SiteImageModel) async -> UIImage
     func cacheFaviconURL(siteURL: URL, faviconURL: URL)
     func clearAllCaches()

test-fixtures/generate-metrics.sh

@@ -4,8 +4,8 @@ set -e
 
 BUILD_LOG_FILE="$1"
 TYPE_LOG_FILE="$2"
-THRESHOLD_UNIT_TEST=15
-THRESHOLD_XCUITEST=15
+THRESHOLD_UNIT_TEST=11
+THRESHOLD_XCUITEST=11
 
 WARNINGS=$(grep -E -v 'SourcePackages/checkouts' "$BUILD_LOG_FILE" \
   | grep -E '^[^ ]+:[0-9]+:[0-9]+: warning:' \