Bump @blockly/field-colour from 5.0.19 to 6.0.12 in /src-editor

Bumps [@blockly/field-colour](https://github.com/RaspberryPiFoundation/blockly-samples/tree/HEAD/plugins/field-colour) from 5.0.19 to 6.0.12.
- [Release notes](https://github.com/RaspberryPiFoundation/blockly-samples/releases)
- [Changelog](https://github.com/RaspberryPiFoundation/blockly-samples/blob/main/plugins/field-colour/CHANGELOG.md)
- [Commits](https://github.com/RaspberryPiFoundation/blockly-samples/commits/@blockly/field-colour@6.0.12/plugins/field-colour)

---
updated-dependencies:
- dependency-name: "@blockly/field-colour"
  dependency-version: 6.0.12
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

src-editor/package-lock.json

@@ -4,7 +4,7 @@
     "private": true,
     "type": "module",
     "dependencies": {
-        "@blockly/field-colour": "^5.0.19",
+        "@blockly/field-colour": "^6.0.12",
         "@blockly/field-multilineinput": "^5.0.17",
         "@blockly/theme-dark": "^7.0.12",
         "@devbookhq/splitter": "^1.4.2",