chore: provider update in upgrade notes (#1172)

* chore: provider update in upgrade notes

* Update upgrading_to_v20.0.md

docs/upgrading_to_v20.0.md

@@ -27,3 +27,8 @@ we must perform a canary upgrade to move workloads onto the new ASM revision. To
 Another difference from the previous module is that the new ASM module does not provide variables for option configuration (e.g. `custom_overlay`, `options`). For the new version these should be managed separately
 outside the module. This is because those options were tightly coupled to pulling down an installer which the new module does not do. To use options specified in the previous module with the new module find the corresponding configuration [here](https://github.com/GoogleCloudPlatform/anthos-service-mesh-packages/tree/main/asm/istio/options) and move the
 config to the mesh configuration for the managed revision.
+
+### Google Cloud Platform Provider upgrade
+The Terraform Kubernetes Engine Module now requires version 4.10 or higher of
+the Google Cloud Platform Provider and 4.10 or higher of
+the Google Cloud Platform Beta Provider.