Remove desktop_capture_generic target

This was a backwards compatible target.

Bug: b/36882554
Change-Id: I1faaf89656a540311af8c68ddd43df6d54ae87b6
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/267000
Reviewed-by: Oleh Prypin <oprypin@google.com>
Commit-Queue: Mirko Bonadei <mbonadei@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#37338}

modules/desktop_capture/BUILD.gn

@@ -293,26 +293,6 @@ if (is_linux || is_chromeos) {
   }
 }
 
-# TODO(mbonadei): Just for backwards compatibility, remove.
-rtc_source_set("desktop_capture_generic") {
-  deps = [
-    ":desktop_capture",
-    ":primitives",
-    "../../api:scoped_refptr",
-    "../../rtc_base/system:rtc_export",
-  ]
-  sources = [
-    "desktop_capture_options.h",
-    "desktop_capturer.h",
-    "desktop_frame_generator.h",
-    "fake_desktop_capturer.h",
-  ]
-  if (rtc_use_x11_extensions) {
-    sources += [ "linux/x11/shared_x_display.h" ]
-    deps += [ "../../api:refcountedbase" ]
-  }
-}
-
 rtc_library("desktop_capture") {
   visibility = [ "*" ]
   defines = []