ci: increase timeout from '12' to '15' minutes to avoid cancel errors

Author: zimeg

.github/workflows/unit-tests-jdk-14.yml

@@ -9,7 +9,7 @@ on:
 jobs:
   build:
     runs-on: ubuntu-latest
-    timeout-minutes: 12
+    timeout-minutes: 15
     strategy:
       matrix:
         java-version: ["14"]

.github/workflows/unit-tests-jdk-17.yml

@@ -9,7 +9,7 @@ on:
 jobs:
   build:
     runs-on: ubuntu-latest
-    timeout-minutes: 12
+    timeout-minutes: 15
     strategy:
       matrix:
         java-version: ["17"]

.github/workflows/unit-tests-jdk-8.yml

@@ -9,7 +9,7 @@ on:
 jobs:
   build:
     runs-on: ubuntu-latest
-    timeout-minutes: 12
+    timeout-minutes: 15
     strategy:
       matrix:
         java-version: ["8"]