Typo in README: 'behavorial' should be 'behavioral'

[Lefgk]

The current README has a small spelling error:

Feature additions and behavorial changes are currently on pause until TypeScript 7.0 is completed.

behavorial has the i and o swapped — should be behavioral.

PR fixing this: #63492

[RyanCavanaugh]

🤖 This is an automated response. I looked for things that might help (duplicates, FAQ entries, etc) but didn't find anything. A human will take a look!