revert pattern matching becaue perf

Author: liliankasem

src/WebJobs.Script/Workers/Rpc/WebHostRpcWorkerChannelManager.cs

@@ -157,9 +157,9 @@ private bool UsePlaceholderChannel(string workerRuntime)
             // Special case: node and PowerShell apps must be read-only to use the placeholder mode channel
             // Also cannot use placeholder worker that is targeting ~3 but has backwards compatibility with V2 enabled
             // TODO: Remove special casing when resolving https://github.com/Azure/azure-functions-host/issues/4534
-            if (workerRuntime.ToLowerInvariant() is RpcWorkerConstants.NodeLanguageWorkerName
-                or RpcWorkerConstants.PowerShellLanguageWorkerName
-                or RpcWorkerConstants.PythonLanguageWorkerName)
+            if (string.Equals(workerRuntime, RpcWorkerConstants.NodeLanguageWorkerName, StringComparison.OrdinalIgnoreCase)
+                || string.Equals(workerRuntime, RpcWorkerConstants.PowerShellLanguageWorkerName, StringComparison.OrdinalIgnoreCase)
+                || string.Equals(workerRuntime, RpcWorkerConstants.PythonLanguageWorkerName, StringComparison.OrdinalIgnoreCase))
             {
                 // Use if readonly and not v2 compatible on ~3 extension
                 return _applicationHostOptions.CurrentValue.IsFileSystemReadOnly && !_environment.IsV2CompatibleOnV3Extension();