UPSTREAM: <carry>: Explicitly include mockgen model package in vendor directory

Include the `github.com/golang/mock/mockgen/model` package as an explicit dependency
to support the mockgen utility. This change is necessary due to the rebasing to v2.8.2
and the downstream fork's reliance on the vendor directory for building the controller image in CI.
Without this explicit inclusion, the package lookup fails with the error:
"cannot find module providing package...import lookup disabled by -mod=vendor".

Author: alebedev87

tools/tools.go

@@ -0,0 +1,13 @@
+package tools
+
+import (
+	// This package is explicitly included to support the mockgen utility,
+	// which was introduced after rebasing to v2.8.2.
+	// The downstream fork builds the image using the vendor directory,
+	// where module lookup is disabled:
+	// "cannot find module providing package github.com/golang/mock/mockgen/model:
+	// import lookup disabled by -mod=vendor".
+	// To ensure the package is included in the vendor directory,
+	// it must be an explicit dependency.
+	_ "github.com/golang/mock/mockgen/model"
+)