feat: drop Guava dependency (#823)

Author: DanySK

build.gradle.kts

@@ -16,7 +16,7 @@ multiJvm {
 }
 
 dependencies {
-    implementation(libs.guava)
+    compileOnly(libs.jsr305)
     testCompileOnly(libs.spotbugs.annotations)
     testImplementation(libs.junit4)
 }

gradle/libs.versions.toml

@@ -1,7 +1,7 @@
 [libraries]
-guava = "com.google.guava:guava:33.4.0-jre"
 junit4 = "junit:junit:4.13.2"
 spotbugs-annotations = "com.github.spotbugs:spotbugs-annotations:4.8.6"
+jsr305 = "com.google.code.findbugs:jsr305:3.0.2"
 
 [plugins]
 gitSemVer = "org.danilopianini.git-sensitive-semantic-versioning-gradle-plugin:3.1.7"

src/main/java/org/danilopianini/util/FlexibleQuadTree.java

@@ -6,8 +6,6 @@
  *******************************************************************************/
 package org.danilopianini.util;
 
-import com.google.common.hash.Hashing;
-
 import javax.annotation.Nonnull;
 import java.io.Serializable;
 import java.util.ArrayDeque;
@@ -515,14 +513,8 @@ public boolean equals(final Object obj) {
         }
 
         @Override
-        @SuppressWarnings("UnstableApiUsage")
         public int hashCode() {
-            return Hashing.murmur3_32_fixed().newHasher()
-                .putDouble(x)
-                .putDouble(y)
-                .putInt(element.hashCode())
-                .hash()
-                .asInt();
+            return Objects.hash(x, y, element);
         }
 
         public boolean isIn(final double sx, final double sy, final double fx, final double fy) {