[FIX] Dependabot not working

Dependabot did not work anymore.
This fixes and adds Docker as well.

Enable dependabot for most recent and supported branches:

This change enables Dependabot for all supported branches, by trying 
to consume dependabot settings 
[`target-branch`](https://docs.github.com/en/code-security/dependabot/dependabot-version-updates/configuration-options-for-the-dependabot.yml-file#target-branch) together with 
[`commit-message.prefix`](https://docs.github.com/en/code-security/dependabot/dependabot-version-updates/configuration-options-for-the-dependabot.yml-file#commit-message)

Fixes: #3168

.github/dependabot.yml

@@ -0,0 +1,50 @@
+version: 2
+updates:
+ -
+ package-ecosystem: "composer"
+ directory: "/"
+ schedule:
+ interval: "daily"
+ allow:
+ - dependency-name: "solarium/solarium"
+ target-branch: "main"
+ commit-message:
+ prefix: "[TASK] 13.0.x-dev "
+ -
+ package-ecosystem: "docker"
+ directory: "/Docker/SolrServer"
+ schedule:
+ interval: "daily"
+ target-branch: "main"
+ commit-message:
+ prefix: "[TASK] 13.0.x-dev "
+
+ # For release-12.0.x
+ -
+ package-ecosystem: "composer"
+ directory: "/"
+ schedule:
+ interval: "daily"
+ allow:
+ - dependency-name: "solarium/solarium"
+ target-branch: "release-12.0.x"
+ commit-message:
+ prefix: "[TASK] 12.0.x-dev "
+ -
+ package-ecosystem: "docker"
+ directory: "/Docker/SolrServer"
+ schedule:
+ interval: "daily"
+ target-branch: "release-12.0.x"
+ commit-message:
+ prefix: "[TASK] 12.0.x-dev "
+
+ # For release-11.6.x
+ -
+ package-ecosystem: "docker"
+ directory: "/Docker/SolrServer"
+ schedule:
+ interval: "daily"
+ target-branch: "release-11.6.x"
+ commit-message:
+ prefix: "[TASK] 11.6.x-dev "