CI: fix dependabot setup

Follow up to: c7f5a82 .
Typo in filename prevented bot to actually work.

Author: larabr

.github/.dependabot.yml .github/dependabot.yml

@@ -6,4 +6,4 @@ updates:
       interval: "daily"
     allow:
       - dependency-name: "playwright"
-    versioning-strategy: increase
+    versioning-strategy: increase