Bump reportlab from 3.6.6 to 3.6.13

Bumps [reportlab](https://www.reportlab.com/) from 3.6.6 to 3.6.13.

---
updated-dependencies:
- dependency-name: reportlab
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

base-requirements.txt

@@ -50,6 +50,6 @@ num2words==0.5.10
 django-polymorphic==3.0.0
 sorl-thumbnail==12.7.0
 docxtpl==0.12.0
-reportlab==3.6.6
+reportlab==3.6.13
 django-extensions==3.1.4
 django-import-export==2.7.1