[Documentation] Typos in `@cached` docs

[geneukum]

📙 Describe the Issue

There are a couple of minor typos in the @cached documentation. The word mechanism is spelled as mecanism and the word trade-off is spelled as tradoff.

🔬 Minimal Reproduction

(https://api.emberjs.com/ember/4.6/functions/@glimmer%2Ftracking/cached)

😕 Actual Behavior

A couple of typos appear in the rendered out API docs for the @cached decorator.

🤔 Expected Behavior

No typos in the rendered out API docs for the @cached decorator.

[geneukum]

This should be fixed by: https://github.com/emberjs/ember.js/pull/20146