letting compile version down for e2e checks

kafka-ui-e2e-checks/pom.xml

@@ -11,8 +11,6 @@
 
     <artifactId>kafka-ui-e2e-checks</artifactId>
     <properties>
-        <maven.compiler.target>1.8</maven.compiler.target>
-        <maven.compiler.source>1.8</maven.compiler.source>
         <junit.version>5.7.0</junit.version>
         <aspectj.version>1.9.6</aspectj.version>
         <allure.version>2.13.7</allure.version>
@@ -173,8 +171,8 @@
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-compiler-plugin</artifactId>
                 <configuration>
-                    <source>15</source>
-                    <target>15</target>
+                    <source>${maven.compiler.source}</source>
+                    <target>${maven.compiler.target}</target>
                 </configuration>
             </plugin>
         </plugins>

kafka-ui-e2e-checks/src/main/java/com/provectus/kafka/ui/screenshots/Screenshooter.java

@@ -115,10 +115,8 @@ public class Screenshooter {
     } else {
       Assertions.assertTrue(
           PIXELS_THRESHOLD >= diff.getDiffSize(),
-          ("""
-                  Amount of differing pixels should be less or equals than %s, actual %s
-                  diff file: %s
-                  """)
+              ("Amount of differing pixels should be less or equals than %s, actual %s\n"+
+                  "diff file: %s")
               .formatted(PIXELS_THRESHOLD, diff.getDiffSize(), FileSystems.getDefault().getPath(fullPathNameDiff).normalize().toAbsolutePath().toString()));
     }
   }