Update sbt-sonatype to 3.9.21 (#401)

* Update sbt-sonatype to 3.9.21

* Update release-drafter.yml

---------

Co-authored-by: Taro L. Saito <leo@xerial.org>

.github/release-drafter.yml

@@ -1,3 +1,39 @@
+name-template: 'v$RESOLVED_VERSION'
+tag-template: 'v$RESOLVED_VERSION'
+categories:
+  - title: '🔥 Breaking Changes'
+    labels:
+      - 'breaking'
+  - title: '🚀 Features'
+    labels:
+      - 'feature'
+      - 'enhancement'
+  - title: '🐛 Bug Fixes'
+    labels:
+      - 'bug'
+  - title: '👋 Deprecated'
+    labels:
+      - 'deprecation'
+  - title: '🔗 Dependency Updates'
+    labels:
+      - 'library-update'
+      - 'dependencies'
+  - title: '🛠  Internal Updates'
+    labels:
+      - 'internal'
+      - 'kaizen'
+      - 'test-library-update'
+      - 'sbt-plugin-update'
+  - title: '📚 Docs'
+    labels:
+      - 'doc'
+change-template: '- $TITLE @$AUTHOR (#$NUMBER)'
+
+template: |
+  ## What's Changed
+  $CHANGES
+  **Full Changelog**: https://github.com/$OWNER/$REPOSITORY/compare/$PREVIOUS_TAG...v$RESOLVED_VERSION
+  
 autolabeler:
   - label: 'doc'
     files:

project/plugins.sbt

@@ -1,4 +1,4 @@
-val SONATYPE_VERSION = sys.env.getOrElse("SONATYPE_VERSION", "3.9.20")
+val SONATYPE_VERSION = sys.env.getOrElse("SONATYPE_VERSION", "3.9.21")
 addSbtPlugin("org.xerial.sbt" % "sbt-sonatype"  % SONATYPE_VERSION)
 addSbtPlugin("com.github.sbt" % "sbt-pgp"       % "2.2.1")
 addSbtPlugin("org.scalameta"  % "sbt-scalafmt"  % "2.5.0")