Ensure float operations in SoundSynthesizerEffects & CompassCalibrator.

[microbit-carlos]

Related PR, which includes files in codal-core like LevelDetectorSPL, and together with this PR it saves >400 bytes of flash:

• Ensure float literals and float versions of math functions are used. codal-core#176

Edit: Also ensured float literals in a couple of other files to avoid implicit double promotion.

[microbit-carlos]

As the PR in codal-core has been merged, I've udpated target-locked.json to point to that commit and that shows the half KB of flash saving from having fewer/smaller math functions included in the build.

[github-actions]

Build diff

Base commit: 73329cea9f963fe3129f7f51c2a668dc50c952e5
Action run: https://github.com/lancaster-university/codal-microbit-v2/actions/runs/12400645876

     VM SIZE    
 -------------- 
  +1.9%     +24    /home/runner/work/codal-microbit-v2/codal-microbit-v2/libraries/codal-core/source/streams/LevelDetectorSPL.cpp
  -2.1%     -16    /home/runner/work/codal-microbit-v2/codal-microbit-v2/libraries/codal-core/source/streams/StreamNormalizer.cpp
  -5.7%     -56    /home/runner/work/codal-microbit-v2/codal-microbit-v2/libraries/codal-core/source/driver-models/Compass.cpp
  -2.1%    -480    [section .text]
  -0.1%    -528    TOTAL

[finneyj]

Looks good - I'm not sure we want to include the target-locked.json though do we @microbit-carlos?

[microbit-carlos]

While it is not really necessary for this PR, I actually do prefer when commits going to codal-microbit-v2 update the target-locked.json file IF they need a commit from any of its dependencies.

Normally the target-locked.json is only updated when a new tag has been created, and that has in some occasions caused microbit-v2-samples to have broken builds.
This happens when the main branch is in that in-between state after merging everything into all the codal repositories, but before creating a codal-microbit-v2 tag with the updated target-locked.json. This has also been a bit annoying when trying to go back to old commits for testing or doing a git bisect, and having to guess what the right codal-core/codal-nrf52 commits were that worked with that specific commit from codal-microbit-v2.
On the other hand, doing this can create merge conflicts if multiple PRs do that, but I'd probably argue that is easy enough to resolve, and having the main branch always in working state does feel worthwhile.

That doesn't strictly applies to this PR though, as it doesn't really need lancaster-university/codal-core@b395ae3 to compile, so happy to remove it in this case.