Add version check

[SergioGasquez]

Added the update check like we do in espup and espflash, I've also added a --skip-update-check flag like we have in those as users requested it for the other packages.

Tests:

Updating version on the package in Cargo.toml to 0.2.1 and running

❯ cargo r -r -- --chip esp32s3 tests --headless
   Compiling esp-generate v0.2.1 (/Users/sergio/Documents/Espressif/forks/esp-generate)
    Finished `release` profile [optimized] target(s) in 3.98s
     Running `target/release/esp-generate --chip esp32s3 tests --headless`
[2025-01-31T07:39:10Z WARN ] 🚀 A new version of esp-generate is available: v0.2.2
[2025-01-31T07:39:10Z WARN ] Current directory is already in a git repository, skipping git initialization

If we add the flag:

❯ cargo r -r -- --chip esp32s3 tests --headless --skip-update-check
    Finished `release` profile [optimized] target(s) in 0.09s
     Running `target/release/esp-generate --chip esp32s3 tests --headless --skip-update-check`
[2025-01-31T07:39:44Z WARN ] Current directory is already in a git repository, skipping git initialization

[bjoernQ]

Thanks!