fix: teku gradlew 9 upgrade (#339)

Before:
https://github.com/ethpandaops/eth-client-docker-image-builder/actions/runs/22992036440/job/66755105995#step:4:895
After:
https://github.com/ethpandaops/eth-client-docker-image-builder/actions/runs/22993775081

Author: barnabasbusa

teku/build.sh

@@ -2,7 +2,8 @@
 
 SCRIPT_DIR=$( cd -- "$( dirname -- "${BASH_SOURCE[0]}" )" &> /dev/null && pwd )
 cd ${SCRIPT_DIR}/../source
-./gradlew -g ../.gradle distDocker
+export GRADLE_USER_HOME="$(pwd)/../.gradle"
+./gradlew distDocker
 docker tag consensys/teku:develop "${target_repository}:${target_tag}"
 docker push "${target_repository}:${target_tag}"
 docker tag consensys/teku:develop "${target_repository}:${target_tag}-${source_git_commit_hash}"

teku/xatu-sidecar.sh

@@ -12,7 +12,8 @@ echo "temu commit hash: $(git rev-parse HEAD)"
 cd ../source
 
 # Build using teku's gradle build process
-./gradlew -g ../.gradle distDocker
+export GRADLE_USER_HOME="$(pwd)/../.gradle"
+./gradlew distDocker
 docker tag consensys/teku:develop "${target_repository}:${target_tag}"
 docker push "${target_repository}:${target_tag}"
 docker tag consensys/teku:develop "${target_repository}:${target_tag}-${source_git_commit_hash}"