Fix some yamllint violations in YML files (#769)

.github/release-drafter.yml

@@ -1,2 +1,4 @@
+# See https://github.com/jenkinsci/.github/blob/master/.github/release-drafter.adoc
+---
 _extends: .github
 tag-template: archetypes-$NEXT_MINOR_VERSION

.github/workflows/release-drafter.yml

@@ -1,5 +1,5 @@
 # Note: additional setup is required, see https://github.com/jenkinsci/.github/blob/master/.github/release-drafter.adoc
-
+---
 name: Release Drafter
 
 on:

common-files/.github/dependabot.yml

@@ -1,12 +1,12 @@
 # https://docs.github.com/code-security/dependabot/dependabot-version-updates/configuring-dependabot-version-updates
-
+---
 version: 2
 updates:
-- package-ecosystem: maven
-  directory: /
-  schedule:
-    interval: monthly
-- package-ecosystem: github-actions
-  directory: /
-  schedule:
-    interval: monthly
+  - package-ecosystem: maven
+    directory: /
+    schedule:
+      interval: monthly
+  - package-ecosystem: github-actions
+    directory: /
+    schedule:
+      interval: monthly

common-files/.github/release-drafter.yml

@@ -1,2 +1,4 @@
+# See https://github.com/jenkinsci/.github/blob/master/.github/release-drafter.adoc
+---
 _extends: .github
 tag-template: ${artifactId}-$NEXT_MINOR_VERSION

common-files/.github/workflows/jenkins-security-scan.yml

@@ -1,13 +1,13 @@
 # More information about the Jenkins security scan can be found at the developer docs: https://www.jenkins.io/redirect/jenkins-security-scan/
-
+---
 name: Jenkins Security Scan
 on:
   push:
     branches:
       - "master"
       - "main"
   pull_request:
-    types: [ opened, synchronize, reopened ]
+    types: [opened, synchronize, reopened]
   workflow_dispatch:
 
 permissions:
@@ -19,5 +19,5 @@ jobs:
   security-scan:
     uses: jenkins-infra/jenkins-security-scan/.github/workflows/jenkins-security-scan.yaml@v2
     with:
-      java-cache: 'maven' # Optionally enable use of a build dependency cache. Specify 'maven' or 'gradle' as appropriate.
-      # java-version: 21 # Optionally specify what version of Java to set up for the build, or remove to use a recent default.
+      java-cache: 'maven'  # Optionally enable use of a build dependency cache. Specify 'maven' or 'gradle' as appropriate.
+      # java-version: 21  # Optionally specify what version of Java to set up for the build, or remove to use a recent default.

common-files/.github/workflows/release-drafter.yml

@@ -1,5 +1,7 @@
 # Automates creation of Release Drafts using Release Drafter
 # More Info: https://github.com/jenkinsci/.github/blob/master/.github/release-drafter.adoc
+---
+name: Release Drafter
 
 on:
   push: