[ObjC] Remove generate_minimal_imports generation option warning

Since protobuf now has `import option` the original idea around this
is reduced; but more importantly, using the option can run into
problems if a build system wants to do layering checks on the
generated code. So...

- Document the problem
- Remove the warning

It may make sense to flip the default on this option back in the future and even deprecated/eventually remove it. The other choice would be to figure out how to make the generation work with the
transitive `import public` problem.

PiperOrigin-RevId: 820681829

Author: thomasvl

src/google/protobuf/compiler/objectivec/file.cc

@@ -836,8 +836,17 @@ void FileGenerator::DetermineNeededDeps(
     PublicDepsHandling public_deps_handling) const {
   // This logic captures the deps that are needed for types thus removing the
   // ones that are only deps because they provide the definitions for custom
-  // options. If protoc gets something like "import options" then this logic can
-  // go away as the non "import options" deps would be the ones needed.
+  // options.
+  //
+  // However, this as the side effect of if something was needed and it was
+  // coming from a `import public` *within* an `import`, then a `#import` will
+  // be generated for that otherwise transitive import. If some build system
+  // wants to do some sort of strict layering checks on the generated code, then
+  // it will fail those checks.
+  //
+  // Since the original intent of this "mode" was to help prune out headers for
+  // custom options, and protobuf now does support `import option`, it likely
+  // makes sense to remove this in the future instead.
 
   if (public_deps_handling == PublicDepsHandling::kForceInclude) {
     for (int i = 0; i < file_->public_dependency_count(); i++) {

src/google/protobuf/compiler/objectivec/generator.cc

@@ -344,17 +344,6 @@ bool ObjectiveCGenerator::GenerateAll(
               << std::endl;
     std::cerr.flush();
   }
-  if (!generation_options.generate_minimal_imports &&
-      !absl::StrContains(options_warnings_suppressions,
-                         "generate_minimal_imports")) {
-    std::cerr << "WARNING: generate_minimal_imports is disabled, this is "
-                 "deprecated and will be removed in the future. If you have a "
-                 "need for disabling it please file an issue at "
-                 "https://github.com/protocolbuffers/protobuf/issues with "
-                 "your use case."
-              << std::endl;
-    std::cerr.flush();
-  }
   if (!generation_options.strip_custom_options &&
       !absl::StrContains(options_warnings_suppressions,
                          "strip_custom_options")) {