Fix misleading error message when CODEOWNERS is out of date

When running `codeownership validate --skip-autocorrect` with an
out-of-date CODEOWNERS file, the error from codeowners-rs says to run
`codeowners generate`, which is the standalone Rust CLI and not
available to users of this gem. Rewrite the message to point to
`bin/codeownership validate` instead.

Fixes #155

Author: dduugg

lib/code_ownership.rb

@@ -231,6 +231,11 @@ def self.validate!(
     else
       ::RustCodeOwners.validate(files)
     end
+  rescue RuntimeError => e
+    raise e.message.gsub(
+      'Run `codeowners generate` to update the CODEOWNERS file',
+      'Run `bin/codeownership validate` to update the CODEOWNERS file'
+    )
   end
 
   # Removes the file annotation (e.g., "# @team TeamName") from a file.

spec/lib/code_ownership_spec.rb

@@ -555,4 +555,20 @@
       end
     end
   end
+
+  describe '.validate!' do
+    context 'when RustCodeOwners raises a codeowners-rs error about the CODEOWNERS file being out of date' do
+      it 'rewrites the error message to reference bin/codeownership validate' do
+        allow(RustCodeOwners).to receive(:validate).and_raise(
+          RuntimeError,
+          "CODEOWNERS out of date. Run `codeowners generate` to update the CODEOWNERS file"
+        )
+
+        expect { CodeOwnership.validate!(autocorrect: false) }.to raise_error(
+          RuntimeError,
+          "CODEOWNERS out of date. Run `bin/codeownership validate` to update the CODEOWNERS file"
+        )
+      end
+    end
+  end
 end