Update on "Reapply "Add (and fix) OSS check that et_operator_library dtype_selective_build builds (#9245)""

This was reverted due to internal CI failure; reapplying with
that fixed (the new Buck target needed to be moved).

Original summary: This wasn't checked, and it's easy to forget to update the all_deps
targets if we don't check. Now we check.

Differential Revision: [D76458040](https://our.internmc.facebook.com/intern/diff/D76458040/)

[ghstack-poisoned]

Author: swolchok

examples/selective_build/targets.bzl

@@ -25,6 +25,22 @@ def define_common_targets():
         ],
     )
 
+    if runtime.is_oss or is_xplat():
+        executorch_generated_lib(
+            name = "select_all_dtype_selective_lib",
+            functions_yaml_target = "//executorch/kernels/portable:functions.yaml",
+            kernel_deps = [
+                "//executorch/kernels/portable:operators",
+            ],
+            # Setting dtype_selective_build without using list or dict selection isn't a
+            # typical use case; we just do it here so that we can test that our mechanism
+            # for getting buck deps right for dtype_selective_build is working.
+            dtype_selective_build = True,
+            deps = [
+                ":select_all_ops",
+            ],
+        )
+
     # Select a list of operators: defined in `ops`
     et_operator_library(
         name = "select_ops_in_list",