Many extensions (e.g. barcode) fail with `lxml.etree.XMLSyntaxError: xmlns:ns1: '&ns_ai;' is not a valid URI` for files with these namespaces

Summary:

Barcode filter does not create a barcode

Steps to reproduce:

Similar error when applying a QRcode

What happened?

No barcode. Error message.

Traceback (most recent call last):
  File "C:\PortableApps\inkscape1.2beta\share\inkscape\extensions\render_barcode.py", line 54, in <module>
    Barcode().run()
  File "C:\PortableApps\inkscape1.2beta\share\inkscape\extensions\inkex\base.py", line 230, in run
    self.load_raw()
  File "C:\PortableApps\inkscape1.2beta\share\inkscape\extensions\inkex\base.py", line 244, in load_raw
    document = self.load(self.file_io)
  File "C:\PortableApps\inkscape1.2beta\share\inkscape\extensions\inkex\base.py", line 471, in load
    document = load_svg(stream)
  File "C:\PortableApps\inkscape1.2beta\share\inkscape\extensions\inkex\elements\_parser.py", line 95, in load_svg
    return etree.parse(stream, parser=SVG_PARSER)
  File "src/lxml/etree.pyx", line 3536, in lxml.etree.parse
  File "src/lxml/parser.pxi", line 1897, in lxml.etree._parseDocument
  File "src/lxml/parser.pxi", line 1917, in lxml.etree._parseFilelikeDocument
  File "src/lxml/parser.pxi", line 1811, in lxml.etree._parseDocFromFilelike
  File "src/lxml/parser.pxi", line 1201, in lxml.etree._BaseParser._parseDocFromFilelike
  File "src/lxml/parser.pxi", line 615, in lxml.etree._ParserContext._handleParseResultDoc
  File "src/lxml/parser.pxi", line 725, in lxml.etree._handleParseResult
  File "src/lxml/parser.pxi", line 654, in lxml.etree._raiseParseError
  File "C:\Users\Gary\AppData\Local\Temp\ink_ext_XXXXXX.svgDSIAL1", line 21
lxml.etree.XMLSyntaxError: xmlns:ns1: '&#38;#38;#38;#38;#38;#38;#38;#38;#38;#38;#38;#38;#38;#38;#38;#38;#38;#38;#38;ns_ai;' is not a valid URI, line 21, column 103

What should have happened?

Placed a barcode on the document.

Version info

Inkscape 1.2-beta (1b65182ce9, 2022-04-05)

    GLib version:     2.72.0
    GTK version:      3.24.33
    glibmm version:   2.66.2
    gtkmm version:    3.24.5
    libxml2 version:  2.9.13
    libxslt version:  1.1.35
    Cairo version:    1.17.6
    Pango version:    1.50.6
    HarfBuzz version: 4.1.0

    OS version:       Windows 7 SP17Vista SP2Vista SP1VistaXP SP3XP SP2XP SP1XP

Also happens in Inkscape 0.92.5 (0ad1ac969f, 2020-08-06) Linux Mint 20

Edited by Nathan Lee