Minor maintenance things (#501)

* validate gradle wrapper jar file

this is extremely important. see the following:

https://blog.gradle.org/wrapper-attack-report
https://github.com/gradle/wrapper-validation-action#the-gradle-wrapper-problem-in-open-source

Signed-off-by: r3g_5z <june@girlboss.ceo>

* update gradle wrapper to 8.1.1

it is necessary to run the gradlew update command twice to actually
update the jar file properly, e.g.:

./gradlew wrapper --gradle-version=8.1.1 --gradle-distribution-sha256-sum=e111cb9948407e26351227dabce49822fb88c37ee72f1d1582a69c68af2e702f
./gradlew wrapper --gradle-version=8.1.1 --gradle-distribution-sha256-sum=e111cb9948407e26351227dabce49822fb88c37ee72f1d1582a69c68af2e702f

Signed-off-by: r3g_5z <june@girlboss.ceo>

* use Gradle toolchain

this allows for better build reproducibility and avoid mix and matching
JDKs from other projects

https://docs.gradle.org/current/userguide/toolchains.html

Signed-off-by: r3g_5z <june@girlboss.ceo>

* update dependencies and fix build errors

Signed-off-by: r3g_5z <june@girlboss.ceo>

---------

Signed-off-by: r3g_5z <june@girlboss.ceo>
Co-authored-by: sk22 <sk22@mailbox.org>

gradle/wrapper/gradle-wrapper.properties

@@ -1,6 +1,7 @@
-#Thu Jan 13 11:33:43 MSK 2022
 distributionBase=GRADLE_USER_HOME
-distributionUrl=https\://services.gradle.org/distributions/gradle-8.0-bin.zip
 distributionPath=wrapper/dists
-zipStorePath=wrapper/dists
+distributionSha256Sum=e111cb9948407e26351227dabce49822fb88c37ee72f1d1582a69c68af2e702f
+distributionUrl=https\://services.gradle.org/distributions/gradle-8.1.1-bin.zip
+networkTimeout=10000
 zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists