Make OPTIONS method on MSC3916 endpoints available without auth #3952

Job	Run time
Unit tests	1m 50s
Build for Windows (windows, amd64)	1m 13s
Linting	4m 33s
Build for Linux (linux, amd64)	46s
WASM build test	0s
Build for Linux (linux, 386)	59s
Initial tests passed	3s
Integration tests	4m 23s
Upgrade tests	7m 8s
Complement (SQLite native)	4m 49s
Sytest (SQLite native)	4m 15s
Complement (SQLite Cgo)	4m 30s
Sytest (SQLite Cgo)	4m 17s
Upgrade tests from HEAD-2	6m 16s
Complement (PostgreSQL)	8m 19s
Sytest (PostgreSQL)	5m 45s
Integration tests passed	2s
Update Docker images	0s
	59m 8s

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