Strict null check terminal Eneironment/actions

Part of #60565

src/tsconfig.strictNullChecks.json

@@ -439,7 +439,9 @@
 		"./vs/workbench/parts/tasks/common/taskTemplates.ts",
 		"./vs/workbench/parts/terminal/browser/terminalWidgetManager.ts",
 		"./vs/workbench/parts/terminal/common/terminal.ts",
+		"./vs/workbench/parts/terminal/common/terminalCommands.ts",
 		"./vs/workbench/parts/terminal/node/terminalCommandTracker.ts",
+		"./vs/workbench/parts/terminal/node/terminalEnvironment.ts",
 		"./vs/workbench/parts/webview/electron-browser/webviewProtocols.ts",
 		"./vs/workbench/parts/welcome/gettingStarted/electron-browser/gettingStarted.ts",
 		"./vs/workbench/parts/welcome/page/electron-browser/vs_code_welcome_page.ts",

src/vs/workbench/parts/terminal/node/terminalEnvironment.ts

@@ -134,7 +134,7 @@ export function getCwd(shell: IShellLaunchConfig, root: Uri, configHelper: ITerm
 		return shell.cwd;
 	}
 
-	let cwd: string;
+	let cwd: string | undefined;
 
 	// TODO: Handle non-existent customCwd
 	if (!shell.ignoreConfigurationCwd) {