Bump github.com/hashicorp/terraform-plugin-sdk/v2 from 2.24.1 to 2.26.0

Bumps [github.com/hashicorp/terraform-plugin-sdk/v2](https://github.com/hashicorp/terraform-plugin-sdk) from 2.24.1 to 2.26.0.
- [Release notes](https://github.com/hashicorp/terraform-plugin-sdk/releases)
- [Changelog](https://github.com/hashicorp/terraform-plugin-sdk/blob/main/CHANGELOG.md)
- [Commits](https://github.com/hashicorp/terraform-plugin-sdk/compare/v2.24.1...v2.26.0)

---
updated-dependencies:
- dependency-name: github.com/hashicorp/terraform-plugin-sdk/v2
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

vendor/google.golang.org/grpc/internal/grpcsync/oncefunc.go

@@ -0,0 +1,32 @@
+/*
+ *
+ * Copyright 2022 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package grpcsync
+
+import (
+	"sync"
+)
+
+// OnceFunc returns a function wrapping f which ensures f is only executed
+// once even if the returned function is executed multiple times.
+func OnceFunc(f func()) func() {
+	var once sync.Once
+	return func() {
+		once.Do(f)
+	}
+}