Inherit _asyncParsing. Do not unset it and _shouldAwait

This is in accordance with how other properties containing information
about the last parse call such as args & processedArgs do not get unset.
Consistency in how repeated parse calls are handled could be improved by
resolving tj#1916.

lib/command.js

@@ -926,15 +926,10 @@ Expecting one of '${allowedValues.join("', '")}'`);
     this._asyncParsing = false;
     this._setShouldAwait();
 
-    try {
-      const userArgs = this._prepareUserArgs(argv, parseOptions);
-      this._parseCommand([], userArgs);
+    const userArgs = this._prepareUserArgs(argv, parseOptions);
+    this._parseCommand([], userArgs);
 
-      return this;
-    } finally {
-      this._asyncParsing = undefined;
-      this._shouldAwait = undefined;
-    }
+    return this;
   }
 
   /**
@@ -960,15 +955,10 @@ Expecting one of '${allowedValues.join("', '")}'`);
     this._asyncParsing = true;
     this._setShouldAwait();
 
-    try {
-      const userArgs = this._prepareUserArgs(argv, parseOptions);
-      await this._parseCommand([], userArgs);
+    const userArgs = this._prepareUserArgs(argv, parseOptions);
+    await this._parseCommand([], userArgs);
 
-      return this;
-    } finally {
-      this._asyncParsing = undefined;
-      this._shouldAwait = undefined;
-    }
+    return this;
   }
 
   /**
@@ -991,9 +981,13 @@ Expecting one of '${allowedValues.join("', '")}'`);
    */
 
   _setShouldAwait() {
-    for (let cmd = this; this._shouldAwait === undefined; cmd = cmd.parent) {
-      this._shouldAwait = cmd._await ?? cmd._asyncParsing;
-    }
+    this._shouldAwait = undefined;
+    let cmd = this;
+    do {
+      this._shouldAwait = cmd._await;
+      cmd = cmd.parent;
+    } while (this._shouldAwait === undefined && cmd);
+    this._shouldAwait ??= this._asyncParsing;
   }
 
   /**
@@ -1199,6 +1193,7 @@ Expecting one of '${allowedValues.join("', '")}'`);
   _dispatchSubcommand(commandName, operands, unknown) {
     const subCommand = this._findCommand(commandName);
     if (!subCommand) this.help({ error: true });
+    subCommand._asyncParsing = this._asyncParsing;
 
     let hookResult;
     hookResult = this._chainOrCallSubCommandHook(hookResult, subCommand, 'preSubcommand');