* Refactor: Update build process and improve memory management
- Commented out library tests in build.zig for clarity.
- Changed minimum Zig version to 0.15.1 in build.zig.zon.
- Modified root.zig to accept a Writer for output instead of using log.
- Updated bandwidth.zig tests to use std.Thread.sleep for consistency.
- Adjusted fast.zig to improve memory allocation handling.
- Enhanced http_latency_tester.zig to manage latencies with allocator.
- Refined speed_worker.zig to utilize std.Thread.sleep for delays.
- Improved measurement_strategy.zig to handle speed measurements with allocator.
- Updated main.zig to flush writer after command execution.
* Fix: Update zli dependency to use URL and hash instead of path
* Fix: Add newline to spinner output for better readability
* switch worksflows to using zig 0.15.1
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Co-authored-by: mikkelam <mikkelarm@gmail.com>
