Update changelog

Author: hc-github-team-tf-provider-devex

.changes/0.12.0.md

@@ -0,0 +1,10 @@
+## 0.12.0 (September 06, 2023)
+
+NOTES:
+
+* all: This Go module has been updated to Go 1.20 per the [Go support policy](https://go.dev/doc/devel/release#policy). It is recommended to review the [Go 1.20 release notes](https://go.dev/doc/go1.20) before upgrading. Any consumers building on earlier Go versions may experience errors. ([#188](https://github.com/hashicorp/terraform-plugin-mux/issues/188))
+
+FEATURES:
+
+* all: Upgrade to protocol versions 5.4 and 6.4, which can significantly reduce memory usage with Terraform 1.6 and later when a configuration includes multiple instances of the same provider ([#185](https://github.com/hashicorp/terraform-plugin-mux/issues/185))
+

.changes/unreleased/FEATURES-20230829-144604.yaml

@@ -1,3 +1,13 @@
+## 0.12.0 (September 06, 2023)
+
+NOTES:
+
+* all: This Go module has been updated to Go 1.20 per the [Go support policy](https://go.dev/doc/devel/release#policy). It is recommended to review the [Go 1.20 release notes](https://go.dev/doc/go1.20) before upgrading. Any consumers building on earlier Go versions may experience errors. ([#188](https://github.com/hashicorp/terraform-plugin-mux/issues/188))
+
+FEATURES:
+
+* all: Upgrade to protocol versions 5.4 and 6.4, which can significantly reduce memory usage with Terraform 1.6 and later when a configuration includes multiple instances of the same provider ([#185](https://github.com/hashicorp/terraform-plugin-mux/issues/185))
+
 ## 0.11.2 (July 14, 2023)
 
 BUG FIXES: