fix: #82 Update jacoco to the latest version that should work with mo…

…dern Java versions.

- See https://stackoverflow.com/a/75161454/8534088

pom.xml

@@ -50,6 +50,7 @@
 		<junit-jupiter.version>5.7.0</junit-jupiter.version>
 		<assertj-core.version>3.18.1</assertj-core.version>
 		<assertj-assertions-generator-maven-plugin.version>2.2.0</assertj-assertions-generator-maven-plugin.version>
+		<jacoco.version>0.8.12</jacoco.version>
 
 		<!-- libraries used for old modules, probably with old versions. May also be used by Kefir. -->
 		<servlet-api.version>2.5</servlet-api.version>
@@ -69,7 +70,7 @@
 			<plugin>
 				<groupId>org.jacoco</groupId>
 				<artifactId>jacoco-maven-plugin</artifactId>
-				<version>0.8.4</version>
+				<version>${jacoco.version}</version>
 				<executions>
 					<execution>
 						<goals>