Further tweak dependabot.yml to resolve warnings (#790)

Address the following warnings:

Dependabot couldn't find a Dockerfile
Dependabot requires a Dockerfile to evaluate your Docker dependencies. It had expected to find one at the path: /Dockerfile.

If this isn't a Docker project, you may wish to disable updates for it in the .github/dependabot.yml config file in this repo.

Dependabot couldn't find a package.json
Dependabot requires a package.json to evaluate your JavaScript dependencies. It had expected to find one at the path: /package.json.

If this isn't a JavaScript project, you may wish to disable updates for it in the .github/dependabot.yml config file in this repo.

Co-authored-by: Thomas Cortes <78750681+Toa741@users.noreply.github.com>

.github/dependabot.yml

@@ -5,13 +5,6 @@
 
 version: 2
 updates:
-  - package-ecosystem: 'docker'
-    directory: '/'
-    schedule:
-      interval: weekly
-    rebase-strategy: auto
-    open-pull-requests-limit: 20
-
   - package-ecosystem: 'github-actions'
     directory: '/'
     schedule:
@@ -23,13 +16,6 @@ updates:
         patterns:
           - '*'
 
-  - package-ecosystem: 'npm'
-    directory: '/'
-    schedule:
-      interval: weekly
-    rebase-strategy: auto
-    open-pull-requests-limit: 20
-
   - package-ecosystem: 'nuget'
     directory: '/'
     schedule: