Do not setup license index on --package-only

We do not need the license index in a --package-only scan
as this is designed to do a fast package detection only scan
which skips the license detection. As license index loading
takes a couple seconds in each case, this makes the
package only scan much faster.

Signed-off-by: Ayan Sinha Mahapatra <asmahapatra@aboutcode.org>

Author: AyanSinhaMahapatra

src/licensedcode/plugin_license.py

@@ -152,6 +152,9 @@ def setup(self, **kwargs):
         This is a cache warmup such that child process inherit from the
         loaded index.
         """
+        if kwargs.get("package_only"):
+            return
+
         from licensedcode.cache import populate_cache
         populate_cache()