client/web: remove 'unsafe-inline' from CSP

I seem to recall I needed this for things to work properly with the vite
dev server, but that doesn't seem to be the case anymore?  Everything
seems to work fine without it.  If we still have issues, we'll need to
look into using a nonce or integrity attribute.

Updates #10261
Fixes tailscale/corp#16266

Signed-off-by: Will Norris <will@tailscale.com>

client/web/web.go

@@ -253,7 +253,7 @@ func (s *Server) serve(w http.ResponseWriter, r *http.Request) {
 		if !s.devMode {
 			w.Header().Set("X-Frame-Options", "DENY")
 			// TODO: use CSP nonce or hash to eliminate need for unsafe-inline
-			w.Header().Set("Content-Security-Policy", "default-src 'self' 'unsafe-inline'; img-src * data:")
+			w.Header().Set("Content-Security-Policy", "default-src 'self'; img-src * data:")
 			w.Header().Set("Cross-Origin-Resource-Policy", "same-origin")
 		}
 	}