Bump version on branch-4.18 to 4.18.1-SNAPSHOT - #4887

The action dtolnay/rust-toolchain@29eef336d9b2848a0b548edc03f92a220660cdb8 is not allowed in apache/bookkeeper 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/configure@3a12b0ab99d9cd590a3e9b5a90ea017210ed9556, 1Password/load-secrets-action/configure@70062d7a876d3eb6334754fa26efd2fbd90c32f2, 1Password/load-secrets-action/configure@92467eb28f72e8255933372f1e0707c567ce2259, 1Password/load-secrets-action/configure@e544b780808654ba8ceba5fb2fe2897103d92ff4, 1Password/load-secrets-action/configure@eb2efd0703da22a93c467f2d1ffbb6826c11e19c, 1Password/load-secrets-action@3a12b0ab99d9cd590a3e9b5a90ea017210ed9556, 1Password/load-secrets-action@70062d7a876d3eb6334754fa26efd2fbd90c32f2, 1Password/load-secrets-action@92467eb28f72e8255933372f1e0707c567ce2259, 1Password/load-secrets-action@e544b780808654ba8ceba5fb2fe2897103d92ff4, 1Password/load-secrets-action@eb2efd0703da22a93c467f2d1ffbb6826c11e...

Node.js 20 is deprecated. The following actions target Node.js 20 but are being forced to run on Node.js 24: actions/cache@v4, actions/checkout@v4, actions/setup-java@v4. For more information see: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/