Added dependency for containerized Ubuntu installation (GH-1655)

Author: Vessel9817

getting-started/setup-building.rst

@@ -797,7 +797,8 @@ some of CPython's modules (for example, ``zlib``).
       $ sudo apt-get install build-essential gdb lcov pkg-config \
             libbz2-dev libffi-dev libgdbm-dev libgdbm-compat-dev liblzma-dev \
             libncurses5-dev libreadline6-dev libsqlite3-dev libssl-dev \
-            lzma lzma-dev tk-dev uuid-dev zlib1g-dev libmpdec-dev libzstd-dev
+            lzma lzma-dev tk-dev uuid-dev zlib1g-dev libmpdec-dev libzstd-dev \
+            inetutils-inetd
 
    Note that Debian 12 and Ubuntu 24.04 do not have the ``libmpdec-dev``
    package.  You can safely remove it from the install list above and the