refactor(cargo-heather): replace tracing with println

[Vaiz]

cargo-heather used tracing only for user-facing info!() output with all structured-logging features disabled (no levels, no targets, no timestamps, no spans). Replace with plain println!() and drop tracing + tracing-subscriber from both the crate and the workspace.

This removes 9 transitive crates (tracing, tracing-core, tracing-subscriber, sharded-slab, thread_local, lazy_static, pin-project-lite, once_cell, cfg-if) from the dependency tree

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 90.0%. Comparing base (17e35dc) to head (23cf173).

Additional details and impacted files

@@           Coverage Diff           @@
##            main     #34     +/-   ##
=======================================
- Coverage   90.0%   90.0%   -0.1%     
=======================================
  Files         15      15             
  Lines        808     805      -3     
=======================================
- Hits         728     725      -3     
  Misses        80      80             

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[Copilot]

Pull request overview

This PR simplifies cargo-heather CLI output by replacing tracing-based user-facing messages with direct println!() calls and removing the now-unused logging dependencies from the crate and workspace.

Changes:

• Removed tracing initialization from the cargo-heather binary entry point.
• Replaced info!() calls with println!() in CLI run/config flows.
• Removed tracing and tracing-subscriber dependencies and associated lockfile entries.

Reviewed changes

Copilot reviewed 5 out of 6 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
crates/cargo-heather/src/bin/cargo-heather/run.rs	Replaces progress and result log output with println!().
crates/cargo-heather/src/bin/cargo-heather/main.rs	Removes tracing subscriber setup from startup.
crates/cargo-heather/src/bin/cargo-heather/config.rs	Replaces fallback config message with println!().
crates/cargo-heather/Cargo.toml	Drops crate-level tracing dependencies.
Cargo.toml	Drops workspace tracing dependency declarations.
Cargo.lock	Removes unused tracing-related packages from the lockfile.

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