Update gradle/actions action to v6

[renovate-bot]

This PR contains the following updates:

Package	Type	Update	Change
gradle/actions	action	major	v5 → v6

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Release Notes

gradle/actions (gradle/actions)

v6

Compare Source

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[snazy]

We need to be careful with this PR, see the release notes linking to this page..

[flyrain]

CI Error message:

Getting action download info
Error: The action gradle/actions/setup-gradle@39e147cb9de83bb9910b8ef8bd7fff0ee20fcd6f is not allowed in apache/polaris because all actions must be from a repository owned by your enterprise, created by GitHub, or match one of the patterns: 1Password/load-secrets-action@13f58eec611f8e5db52ec16247f58c508398f3e6, 1Password/load-secrets-action@8d0d610af187e78a2772c2d18d627f4c52d3fbfb, 1Password/load-secrets-action@dafbe7cb03502b260e2b2893c753c352eee545bf, AdoptOpenJDK/install-jdk@*, BobAnkh/auto-generate-changelog@*, DavidAnson/markdownlint-cli2-action@07035fd053f7be764496c0f8d8f9f41f98305101, DavidAnson/markdownlint-cli2-action@30a0e04f1870d58f8d717450cc6134995f993c63, EnricoMi/publish-unit-test-result-action@*, JamesIves/github-pages-deploy-action@4a3abc783e1a24aeb44c16e869ad83caf6b4cc23, JamesIves/github-pages-deploy-action@d92aa235d04922e8f08b40ce78cc5442fcfbfa2f, JetBrains/qodana-action@89eb4357efd2b52e639f3216e63edaf33b82622b, Jimver/cuda-toolkit@6008063726ffe3309d1b22e413d9e88fed91a2f2...