Exclude benchmarks from dependabot (#407)

Co-authored-by: Hugo van Kemenade <[email protected]>

Author: maurycy

.github/dependabot.yml

@@ -2,5 +2,7 @@ version: 2
 updates:
   - package-ecosystem: "pip"
     directory: "/pyperformance/requirements"
+    exclude-paths:
+      - "pyperformance/data-files/"
     schedule:
       interval: "monthly"