chore(deps): bump github.com/hashicorp/terraform-plugin-mux

Bumps [github.com/hashicorp/terraform-plugin-mux](https://github.com/hashicorp/terraform-plugin-mux) from 0.16.0 to 0.20.0.
- [Release notes](https://github.com/hashicorp/terraform-plugin-mux/releases)
- [Changelog](https://github.com/hashicorp/terraform-plugin-mux/blob/main/CHANGELOG.md)
- [Commits](hashicorp/terraform-plugin-mux@v0.16.0...v0.20.0)

---
updated-dependencies:
- dependency-name: github.com/hashicorp/terraform-plugin-mux
  dependency-version: 0.20.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

go.mod

@@ -6,12 +6,12 @@ toolchain go1.24.0
 
 require (
 	github.com/golangci/golangci-lint v1.50.1
-	github.com/google/go-cmp v0.6.0
+	github.com/google/go-cmp v0.7.0
 	github.com/hashicorp/terraform-plugin-framework v1.11.0
 	github.com/hashicorp/terraform-plugin-framework-jsontypes v0.1.0
 	github.com/hashicorp/terraform-plugin-framework-validators v0.12.0
-	github.com/hashicorp/terraform-plugin-go v0.23.0
-	github.com/hashicorp/terraform-plugin-mux v0.16.0
+	github.com/hashicorp/terraform-plugin-go v0.28.0
+	github.com/hashicorp/terraform-plugin-mux v0.20.0
 	github.com/hashicorp/terraform-plugin-sdk/v2 v2.34.0
 	github.com/hashicorp/terraform-plugin-testing v1.9.0
 	github.com/mackerelio/mackerel-client-go v0.36.0
@@ -41,7 +41,7 @@ require (
 	github.com/breml/bidichk v0.2.3 // indirect
 	github.com/breml/errchkjson v0.3.0 // indirect
 	github.com/butuzov/ireturn v0.1.1 // indirect
-	github.com/cespare/xxhash/v2 v2.2.0 // indirect
+	github.com/cespare/xxhash/v2 v2.3.0 // indirect
 	github.com/charithe/durationcheck v0.0.9 // indirect
 	github.com/chavacava/garif v0.0.0-20220630083739-93517212f375 // indirect
 	github.com/cloudflare/circl v1.3.7 // indirect
@@ -88,7 +88,7 @@ require (
 	github.com/hashicorp/go-cty v1.4.1-0.20200414143053-d3edf31b6320 // indirect
 	github.com/hashicorp/go-hclog v1.6.3 // indirect
 	github.com/hashicorp/go-multierror v1.1.1 // indirect
-	github.com/hashicorp/go-plugin v1.6.0 // indirect
+	github.com/hashicorp/go-plugin v1.6.3 // indirect
 	github.com/hashicorp/go-uuid v1.0.3 // indirect
 	github.com/hashicorp/go-version v1.7.0 // indirect
 	github.com/hashicorp/hc-install v0.7.0 // indirect
@@ -98,7 +98,7 @@ require (
 	github.com/hashicorp/terraform-exec v0.21.0 // indirect
 	github.com/hashicorp/terraform-json v0.22.1 // indirect
 	github.com/hashicorp/terraform-plugin-log v0.9.0 // indirect
-	github.com/hashicorp/terraform-registry-address v0.2.3 // indirect
+	github.com/hashicorp/terraform-registry-address v0.2.5 // indirect
 	github.com/hashicorp/terraform-svchost v0.1.1 // indirect
 	github.com/hashicorp/yamux v0.1.1 // indirect
 	github.com/hexops/gotextdiff v1.0.3 // indirect
@@ -176,7 +176,7 @@ require (
 	github.com/ssgreg/nlreturn/v2 v2.2.1 // indirect
 	github.com/stbenjam/no-sprintf-host-port v0.1.1 // indirect
 	github.com/stretchr/objx v0.5.0 // indirect
-	github.com/stretchr/testify v1.8.1 // indirect
+	github.com/stretchr/testify v1.8.3 // indirect
 	github.com/subosito/gotenv v1.4.1 // indirect
 	github.com/tdakkota/asciicheck v0.1.1 // indirect
 	github.com/tetafro/godot v1.4.11 // indirect
@@ -197,19 +197,19 @@ require (
 	go.uber.org/atomic v1.7.0 // indirect
 	go.uber.org/multierr v1.6.0 // indirect
 	go.uber.org/zap v1.17.0 // indirect
-	golang.org/x/crypto v0.35.0 // indirect
+	golang.org/x/crypto v0.37.0 // indirect
 	golang.org/x/exp v0.0.0-20220722155223-a9213eeb770e // indirect
 	golang.org/x/exp/typeparams v0.0.0-20220827204233-334a2380cb91 // indirect
 	golang.org/x/mod v0.17.0 // indirect
-	golang.org/x/net v0.25.0 // indirect
-	golang.org/x/sync v0.11.0 // indirect
-	golang.org/x/sys v0.30.0 // indirect
-	golang.org/x/text v0.22.0 // indirect
+	golang.org/x/net v0.39.0 // indirect
+	golang.org/x/sync v0.13.0 // indirect
+	golang.org/x/sys v0.32.0 // indirect
+	golang.org/x/text v0.24.0 // indirect
 	golang.org/x/tools v0.21.1-0.20240508182429-e35e4ccd0d2d // indirect
 	google.golang.org/appengine v1.6.8 // indirect
-	google.golang.org/genproto/googleapis/rpc v0.0.0-20240227224415-6ceb2ff114de // indirect
-	google.golang.org/grpc v1.63.2 // indirect
-	google.golang.org/protobuf v1.34.0 // indirect
+	google.golang.org/genproto/googleapis/rpc v0.0.0-20250218202821-56aae31c358a // indirect
+	google.golang.org/grpc v1.72.1 // indirect
+	google.golang.org/protobuf v1.36.6 // indirect
 	gopkg.in/ini.v1 v1.67.0 // indirect
 	gopkg.in/yaml.v2 v2.4.0 // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect