rules_go 0.25.0 removed support for go_rule

[fmeum]

The go_rule wrapper has been removed in rules_go 0.25.0, which is also the first version of rules_go with support for Bazel 4.0.0.

I believe that the following patch helps:

--- gomock.bzl
+++ gomock.bzl
@@ -1,4 +1,4 @@
-load("@io_bazel_rules_go//go:def.bzl", "go_binary", "go_context", "go_path", "go_rule")
+load("@io_bazel_rules_go//go:def.bzl", "go_binary", "go_context", "go_path")
 load("@io_bazel_rules_go//go/private:providers.bzl", "GoLibrary", "GoPath")

 _MOCKGEN_TOOL = "@com_github_golang_mock//mockgen"
@@ -55,7 +55,7 @@
         },
     )

-_gomock_source = go_rule(
+_gomock_source = rule(
     _gomock_source_impl,
     attrs = {
         "library": attr.label(
@@ -107,7 +107,9 @@
             cfg = "exec",
             mandatory = False,
         ),
+        "_go_context": attr.label(default = "@io_bazel_rules_go//:go_context_data"),
     },
+    toolchains = ["@io_bazel_rules_go//go:toolchain"],
 )

 def gomock(name, library, out, **kwargs):
@@ -186,7 +188,7 @@
         mnemonic = "GoMockReflectProgOnlyGen"
     )

-_gomock_prog_gen = go_rule(
+_gomock_prog_gen = rule(
     _gomock_prog_gen_impl,
     attrs = {
         "library": attr.label(
@@ -211,7 +213,9 @@
             cfg = "exec",
             mandatory = False,
         ),
+        "_go_context": attr.label(default = "@io_bazel_rules_go//:go_context_data"),
     },
+    toolchains = ["@io_bazel_rules_go//go:toolchain"],
 )

 def _gomock_prog_exec_impl(ctx):
@@ -239,7 +243,7 @@
         mnemonic = "GoMockReflectExecOnlyGen",
     )

-_gomock_prog_exec = go_rule(
+_gomock_prog_exec = rule(
     _gomock_prog_exec_impl,
     attrs = {
         "library": attr.label(
@@ -289,7 +293,9 @@
             cfg = "exec",
             mandatory = False,
         ),
+        "_go_context": attr.label(default = "@io_bazel_rules_go//:go_context_data"),
     },
+    toolchains = ["@io_bazel_rules_go//go:toolchain"],
 )

 def _handle_shared_args(ctx, args):