Playground: `strict=true` in urls doesn't work

[DetachHead]

Repro: https://www.typescriptlang.org/play?strict=true&ts=4.4.0-dev.20210702#code/C4JwngBA3gsAUPAvhAxgQ2CgFgCgKYCU08EpqA9gHYDOwEAltQMqj2UDmEAvBMGAA55yAMwh5uXHgHJaINuykky9UTkYs5HIrDhk9YgHTByAVX6CQAYTTU8OIgHoHEAPIAjAFZ4UdRhBG8AuJSAK6UANaU5ADulIq6ZIhKpCoQOHyCAeKS0rLyUtrJ+nhGpuZ4VjZ2js5RYiAg5CBFSXCIQA

Expected behavior:
strict flag is enabled when it's in the url
Actual behavior:
strict flag is not enabled

[orta]

strict is default in the playground, this could be a UI bug

[orta]

probably related #1922

[typescript-bot]

Hello! As per #2804, we are automatically closing all open issues. Please see #2804 for a description of what issues and PRs can be accepted going forward.