update gradle to version 7.6
diff --git a/build/docker/ubuntu-jammy/Dockerfile b/build/docker/ubuntu-jammy/Dockerfile
index f6b7d04..4ef7a54 100644
--- a/build/docker/ubuntu-jammy/Dockerfile
+++ b/build/docker/ubuntu-jammy/Dockerfile
@@ -162,7 +162,7 @@
   haxelib setup --always /usr/share/haxe/lib && \
   haxelib install --always hxcpp 2>&1 > /dev/null
 
-ENV GRADLE_VERSION="7.5.1"
+ENV GRADLE_VERSION="7.6"
 RUN apt-get install -y --no-install-recommends \
   `# Java dependencies` \
   ant \
@@ -171,7 +171,7 @@
   openjdk-11-jdk-headless && \
   `# Gradle` \
   wget https://services.gradle.org/distributions/gradle-$GRADLE_VERSION-bin.zip -q -O /tmp/gradle-$GRADLE_VERSION-bin.zip && \
-  (echo "f6b8596b10cce501591e92f229816aa4046424f3b24d771751b06779d58c8ec4  /tmp/gradle-$GRADLE_VERSION-bin.zip" | sha256sum -c -) && \
+  (echo "03c0f018d043de73187fe87d1798f4c8f494aceed1c6158b0919367926a19e4d  /tmp/gradle-$GRADLE_VERSION-bin.zip" | sha256sum -c -) && \
   unzip -d /tmp /tmp/gradle-$GRADLE_VERSION-bin.zip && \
   mv /tmp/gradle-$GRADLE_VERSION /usr/local/gradle && \
   ln -s /usr/local/gradle/bin/gradle /usr/local/bin