deps: downgrade hashicorp/terraform-plugin-go to v0.21.0

Pending release of terraform-plugin-framework@v1.6.0

Ref: hashicorp/terraform-plugin-go#380

go.mod

@@ -1,6 +1,8 @@
 module github.com/cloudflare/terraform-provider-cloudflare
 
-go 1.20
+go 1.21
+
+toolchain go1.21.7
 
 require (
 	github.com/agext/levenshtein v1.2.3 // indirect
@@ -14,8 +16,8 @@ require (
 	github.com/hashicorp/go-plugin v1.6.0 // indirect
 	github.com/hashicorp/go-uuid v1.0.3 // indirect
 	github.com/hashicorp/hcl/v2 v2.19.1 // indirect
-	github.com/hashicorp/terraform-plugin-go v0.22.0
-	github.com/hashicorp/terraform-plugin-sdk/v2 v2.33.0
+	github.com/hashicorp/terraform-plugin-go v0.21.0
+	github.com/hashicorp/terraform-plugin-sdk/v2 v2.32.0
 	github.com/hashicorp/yamux v0.1.1 // indirect
 	github.com/mattn/go-isatty v0.0.20 // indirect
 	github.com/mitchellh/go-testing-interface v1.14.1 // indirect
@@ -42,7 +44,7 @@ require (
 	github.com/hashicorp/terraform-plugin-framework v1.5.0
 	github.com/hashicorp/terraform-plugin-framework-validators v0.12.0
 	github.com/hashicorp/terraform-plugin-log v0.9.0
-	github.com/hashicorp/terraform-plugin-mux v0.15.0
+	github.com/hashicorp/terraform-plugin-mux v0.14.0
 	github.com/hashicorp/terraform-plugin-testing v1.6.0
 	github.com/stretchr/testify v1.8.4
 )

go.sum

@@ -118,12 +118,16 @@ github.com/hashicorp/terraform-plugin-framework v1.5.0 h1:8kcvqJs/x6QyOFSdeAyEgs
 github.com/hashicorp/terraform-plugin-framework v1.5.0/go.mod h1:6waavirukIlFpVpthbGd2PUNYaFedB0RwW3MDzJ/rtc=
 github.com/hashicorp/terraform-plugin-framework-validators v0.12.0 h1:HOjBuMbOEzl7snOdOoUfE2Jgeto6JOjLVQ39Ls2nksc=
 github.com/hashicorp/terraform-plugin-framework-validators v0.12.0/go.mod h1:jfHGE/gzjxYz6XoUwi/aYiiKrJDeutQNUtGQXkaHklg=
+github.com/hashicorp/terraform-plugin-go v0.21.0 h1:VSjdVQYNDKR0l2pi3vsFK1PdMQrw6vGOshJXMNFeVc0=
+github.com/hashicorp/terraform-plugin-go v0.21.0/go.mod h1:piJp8UmO1uupCvC9/H74l2C6IyKG0rW4FDedIpwW5RQ=
 github.com/hashicorp/terraform-plugin-go v0.22.0 h1:1OS1Jk5mO0f5hrziWJGXXIxBrMe2j/B8E+DVGw43Xmc=
 github.com/hashicorp/terraform-plugin-go v0.22.0/go.mod h1:mPULV91VKss7sik6KFEcEu7HuTogMLLO/EvWCuFkRVE=
 github.com/hashicorp/terraform-plugin-log v0.9.0 h1:i7hOA+vdAItN1/7UrfBqBwvYPQ9TFvymaRGZED3FCV0=
 github.com/hashicorp/terraform-plugin-log v0.9.0/go.mod h1:rKL8egZQ/eXSyDqzLUuwUYLVdlYeamldAHSxjUFADow=
+github.com/hashicorp/terraform-plugin-mux v0.14.0/go.mod h1:UzkNhewtpuqSnBvo1ZXSagAxu+hQ+Ir3F5Mpm86dWn0=
 github.com/hashicorp/terraform-plugin-mux v0.15.0 h1:+/+lDx0WUsIOpkAmdwBIoFU8UP9o2eZASoOnLsWbKME=
 github.com/hashicorp/terraform-plugin-mux v0.15.0/go.mod h1:9ezplb1Dyq394zQ+ldB0nvy/qbNAz3mMoHHseMTMaKo=
+github.com/hashicorp/terraform-plugin-sdk/v2 v2.32.0/go.mod h1:LxQzs7AQl/5JE1IGFd6LX8E4A0InRJ/7s245gOmsejA=
 github.com/hashicorp/terraform-plugin-sdk/v2 v2.33.0 h1:qHprzXy/As0rxedphECBEQAh3R4yp6pKksKHcqZx5G8=
 github.com/hashicorp/terraform-plugin-sdk/v2 v2.33.0/go.mod h1:H+8tjs9TjV2w57QFVSMBQacf8k/E1XwLXGCARgViC6A=
 github.com/hashicorp/terraform-plugin-testing v1.6.0 h1:Wsnfh+7XSVRfwcr2jZYHsnLOnZl7UeaOBvsx6dl/608=