[1.5.0] Acquire and Release feature

What's changed

Added

• Added Elixir 1.19 and Erlang 28 support to CI.
• Added acquire/2 and release/2 functions for manual worker management in long-running operations. These functions provide automatic cleanup when the caller process crashes. See the documentation for more details.

Changed

• Refactored run/3 to use the new acquire/2 and release/2 internally, ensuring consistent behavior between manual and automatic worker management.
• Refactored the caller monitoring system. Pools now store monitor references to enable proper cleanup and prevent double-release vulnerabilities.