copilot: Fix missing sign-out button when Zed is the edit prediction provider #46161

Job	Run time
Check Postgres and Protobuf migrations, mergability	12s
(Linux) Run Clippy and tests	10m 30s
(macOS) Run Clippy and tests	7m 0s
(Linux) Build Remote Server	1m 22s
Check formatting and spelling	28s
(Windows) Run Clippy	4m 14s
(Windows) Run Tests	0s
Create a macOS bundle	0s
Linux arm64 release bundle	0s
Linux x86_x64 release bundle	0s
Auto release preview	0s
	23m 46s

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