Removed SourceForge (#1487)

README.md

@@ -18,7 +18,6 @@ Currently supported App sources:
   - [F-Droid](https://f-droid.org/)
   - Third Party F-Droid Repos
   - [IzzyOnDroid](https://android.izzysoft.de/)
-  - [SourceForge](https://sourceforge.net/)
   - [SourceHut](https://git.sr.ht/)
 - Other - General:
   - [APKPure](https://apkpure.net/)

lib/providers/source_provider.dart

@@ -736,7 +736,6 @@ class SourceProvider {
         FDroid(),
         FDroidRepo(),
         IzzyOnDroid(),
-        SourceForge(),
         SourceHut(),
         APKPure(),
         Aptoide(),