Prevent concurrent execution of tests on GH actions

Author: JulianVennen

.github/workflows/release.yml

@@ -1,8 +1,13 @@
 name: Release
+
 on:
   push:
     tags:
       - '*.*.*'
+
+concurrency:
+  group: java-exaroton-api
+
 jobs:
   release:
     runs-on: ubuntu-latest

.github/workflows/test.yml

@@ -1,9 +1,14 @@
 name: Test
+
 on:
   push:
     branches:
       - '*'
   pull_request:
+
+concurrency:
+  group: java-exaroton-api
+
 jobs:
   test:
     runs-on: ubuntu-latest