Rollback to stable OkHttp

There's some weird crashes related to it. Happy Eyeballs will return once we upgrade again.

app/src/main/java/eu/kanade/tachiyomi/network/NetworkHelper.kt

@@ -27,7 +27,7 @@ class NetworkHelper(context: Context) {
                 .cookieJar(cookieManager)
                 .connectTimeout(30, TimeUnit.SECONDS)
                 .readTimeout(30, TimeUnit.SECONDS)
-                .fastFallback(true)
+                // .fastFallback(true) // TODO: re-enable when OkHttp 5 is stabler
                 .addInterceptor(UserAgentInterceptor())
 
             if (preferences.verboseLogging()) {

gradle/libs.versions.toml

@@ -1,6 +1,6 @@
 [versions]
 aboutlib_version = "8.9.4"
-okhttp_version = "5.0.0-alpha.6"
+okhttp_version = "4.9.3"
 nucleus_version = "3.0.0"
 coil_version = "2.0.0-rc03"
 conductor_version = "3.1.2"