Rollup merge of #131594 - fmease:rustdoc-mv-obj-safe-dyn-compat, r=no…

…triddle

rustdoc: Rename "object safe" to "dyn compatible"

Supersedes #126554:

1. In line with [T-lang's latest resolution](rust-lang/lang-team#286 (comment)).
2. More comprehensive: Not only updates user-facing text but also source code.

Part of #130852.

Doesn't update rustdoc-JSON (will be filed separately).

r? `@notriddle` (rust-lang/lang-team#286) `@GuillaumeGomez` (for visibility)