deps: update to @bpmn-io/feel-editor@1.6.1

[marstamm]

Proposed Changes

Update feel-editor to not include unsafe evaluation. This fixes the feel-editor. To test this, use the build artifacts since unsafe eval is allowed in the dev setup:

npm ci
npm run build

closes #4398

Checklist

To ensure you provided everything we need to look at your PR:

• [x] Brief textual description of the changes present
• [x] Visual demo attached
• [x] Steps to try out present, i.e. using the @bpmn-io/sr tool
• [x] Related issue linked via Closes {LINK_TO_ISSUE} or Related to {LINK_TO_ISSUE}