anv: Import mako templates only during execution of anv_extensions

anv_extensions usage from anv_icd was bringing the unwanted dependency
of mako templates for the latter. We don't want that since it will
force the dependency even for distributable tarballs which was not
needed until now.

Jason suggested this approach.

v2: Patch simplification (Jason).

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=104551
Fixes: 0ab04ba979 ("anv: Use python to generate ICD json files")
Cc: Jason Ekstrand <jason.ekstrand@intel.com>
Cc: Emil Velikov <emil.velikov@collabora.com>
Signed-off-by: Andres Gomez <agomez@igalia.com>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>

src/intel/vulkan/anv_extensions.py

@@ -29,8 +29,6 @@ import copy
 import re
 import xml.etree.cElementTree as et
 
-from mako.template import Template
-
 MAX_API_VERSION = '1.0.57'
 
 class Extension:
@@ -160,7 +158,7 @@ def _init_exts_from_xml(xml):
         ext = ext_name_map[ext_name]
         ext.type = ext_elem.attrib['type']
 
-_TEMPLATE = Template(COPYRIGHT + """
+_TEMPLATE = COPYRIGHT + """
 #include "anv_private.h"
 
 #include "vk_util.h"
@@ -258,7 +256,7 @@ VkResult anv_EnumerateDeviceExtensionProperties(
 
     return vk_outarray_status(&out);
 }
-""")
+"""
 
 if __name__ == '__main__':
     parser = argparse.ArgumentParser()
@@ -282,5 +280,7 @@ if __name__ == '__main__':
         'device_extensions': [e for e in EXTENSIONS if e.type == 'device'],
     }
 
+    from mako.template import Template
+
     with open(args.out, 'w') as f:
-        f.write(_TEMPLATE.render(**template_env))
+        f.write(Template(_TEMPLATE).render(**template_env))