Remove null check (#7)

* Remove null check

* Change syntax

Author: nakamura-to

.github/workflows/build.yml

@@ -2,10 +2,9 @@ name: Build
 
 on:
   push:
-    branches:
-      - main
-    pull_request:
-      - main
+    branches: [ master ]
+  pull_request:
+    branches: [ master ]
   workflow_dispatch:
 
 jobs:

.github/workflows/release-drafter.yml

@@ -2,8 +2,7 @@ name: Release Drafter
 
 on:
   push:
-    branches:
-      - main
+    branches: [ master ]
   workflow_dispatch:
 
 jobs:

build.gradle.kts

@@ -139,10 +139,10 @@ rootProject.apply {
         newVersionCommitMessage = "[Gradle Release Plugin] - [skip ci] new version commit: "
 
         val releaseVersion = project.properties["release.releaseVersion"]?.toString()
-        checkNotNull(releaseVersion)
-
-        git {
-            requireBranch = "release/$releaseVersion"
+        if (releaseVersion != null) {
+            git {
+                requireBranch = "release/$releaseVersion"
+            }
         }
     }