chore!: Update blockly-keyboard-experimentation for Blockly v12.

[gonfunko]

This PR fixes #301 by updating the keyboard experimentation plugin to use and depend on Blockly v12.

[maribethb]

I would recommend you mark this as a breaking change since you are updating the minimum peer dependency on blockly. It will make it easier to know which is the latest safe version for folks that aren't using v12 yet. I don't know how strict you're being about versioning though.

[rachel-fenichel]

This PR requires you to use --force on installation, because of a compatibility issue with the field-colour plugin:

npm ERR! code ERESOLVE
npm ERR! ERESOLVE could not resolve
npm ERR! 
npm ERR! While resolving: @blockly/[email protected]
npm ERR! Found: [email protected]
npm ERR! node_modules/blockly
npm ERR!   dev blockly@"12.0.0-beta.2" from the root project
npm ERR! 
npm ERR! Could not resolve dependency:
npm ERR! peer blockly@"^11.0.0" from @blockly/[email protected]
npm ERR! node_modules/@blockly/field-colour
npm ERR!   dev @blockly/field-colour@"^5.0.7" from the root project
npm ERR! 
npm ERR! Conflicting peer dependency: [email protected]
npm ERR! node_modules/blockly
npm ERR!   peer blockly@"^11.0.0" from @blockly/[email protected]
npm ERR!   node_modules/@blockly/field-colour
npm ERR!     dev @blockly/field-colour@"^5.0.7" from the root project
npm ERR! 
npm ERR! Fix the upstream dependency conflict, or retry
npm ERR! this command with --force or --legacy-peer-deps
npm ERR! to accept an incorrect (and potentially broken) dependency resolution.
npm ERR! 
npm ERR! 
npm ERR! For a full report see:
npm ERR! /home/fenichel/.npm/_logs/2025-03-21T22_12_03_017Z-eresolve-report.txt

Some options:

1. Tell everyone to use --force forevermore
2. Make a beta for field-colour?
3. Remove the colour field blocks, now that we have the rest of the playground in place and also can use more complex widgets through microbit

[rachel-fenichel]

I think we should remove the colour field and its uses so that we don't require --force. @gonfunko @maribethb any objections?

[maribethb]

github needs to let me emoji react to commits already - glad the overrides worked!