mojo: Allow building with jinja2 3.0.0

jinja2 3.0.0 changes compile_templates() so that py_compile is no longer
an accepted parameter. In jinja2 2.10.x, the py_compile parameter is
ignored for Python 3. Since Python 2 is EOL, there is thus no reason to
continue passing the parameter. Remove it to allow mojo to build with
both jinja2 3.0.0 and 2.10.x.

Signed-off-by: Paul Elder <paul.elder@ideasonboard.com>
Change-Id: Ic3274b1d86a5fc532819bd581eeecb175ba7e31d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2908396
Reviewed-by: Oksana Zhuravlova <oksamyt@chromium.org>
Commit-Queue: Oksana Zhuravlova <oksamyt@chromium.org>
Cr-Commit-Position: refs/heads/master@{#886322}

mojo/public/tools/mojom/mojom/generate/template_expander.py

@@ -79,5 +79,4 @@ def PrecompileTemplates(generator_modules, output_dir):
         output_dir, "%s.zip" % generator.GetTemplatePrefix()),
                                 extensions=["tmpl"],
                                 zip="stored",
-                                py_compile=sys.version_info.major < 3,
                                 ignore_errors=False)