Remove dependabot reviewers

Remove dependabot reviewers as the option is deprecated.

Author: martincostello

.github/dependabot.yml

@@ -7,8 +7,6 @@ updates:
     interval: weekly
     time: "05:30"
     timezone: Europe/London
-  reviewers:
-    - "martincostello"
 - package-ecosystem: nuget
   directory: "/"
   groups:
@@ -27,8 +25,6 @@ updates:
     interval: weekly
     time: "05:30"
     timezone: Europe/London
-  reviewers:
-    - "martincostello"
   open-pull-requests-limit: 99
 - package-ecosystem: npm
   directory: "/src/TodoApp"
@@ -44,6 +40,4 @@ updates:
     interval: weekly
     time: "05:30"
     timezone: Europe/London
-  reviewers:
-    - "martincostello"
   open-pull-requests-limit: 99