testing/testcase: ignore puppeteer in ldd check

for https://lab.nexedi.com/nexedi/slapos/merge_requests/725

RuntimeError: /srv/slapgrid/slappart9/srv/testnode/cxm/inst/test0-0/tmp/soft/503f3967022ee2febfbb1f4cb30c3a0f/parts/theia/node_modules/puppeteer/.local-chromium/linux-722234/chrome-linux/chrome has some not found libraries:
	libX11-xcb.so.1 => not found
	libXcomposite.so.1 => not found
	libXcursor.so.1 => not found
	libXdamage.so.1 => not found
	libXfixes.so.3 => not found
	libXi.so.6 => not found
	libXrender.so.1 => not found
	libXtst.so.6 => not found
	libnss3.so => not found
	libnssutil3.so => not found
	libsmime3.so => not found
	libnspr4.so => not found
	libcups.so.2 => not found
	libXss.so.1 => not found
	libXrandr.so.2 => not found
	libasound.so.2 => not found
	libatk-1.0.so.0 => not found
	libatk-bridge-2.0.so.0 => not found
	libpangocairo-1.0.so.0 => not found
	libpango-1.0.so.0 => not found
	libcairo.so.2 => not found
	libatspi.so.0 => not found
	libgtk-3.so.0 => not found
	libgdk-3.so.0 => not found
	libgdk_pixbuf-2.0.so.0 => not found