asyncio.subprocess: Fix a typo in doc (#92030)

Remove a confusion for read method in asyncio-subprocess doc for stderr StreamReader instance

Author: Harsh-br0

Doc/library/asyncio-subprocess.rst

@@ -275,7 +275,7 @@ their completion.
       Use the :meth:`communicate` method rather than
       :attr:`process.stdin.write() <stdin>`,
       :attr:`await process.stdout.read() <stdout>` or
-      :attr:`await process.stderr.read <stderr>`.
+      :attr:`await process.stderr.read() <stderr>`.
       This avoids deadlocks due to streams pausing reading or writing
       and blocking the child process.