src/sage/rings/padics/meson.build: add padic_lattice_element_test.py

Run tools/update-meson.py to install the new pytest source file.

Author: orlitzky

src/sage/rings/padics/meson.build

@@ -39,6 +39,7 @@ py.install_sources(
   'padic_generic_element.pxd',
   'padic_generic_element.pyx',
   'padic_lattice_element.py',
+  'padic_lattice_element_test.py',
   'padic_printing.pxd',
   'padic_printing.pyx',
   'padic_relaxed_element.pxd',