build: remove websocket support from deltachat-jsonrpc

WebSocket support is not used
and is not maintained. It still uses
outdated axum 0.7 version
and does not have any authentication.

Delta Chat Desktop has a new browser target
that implements WebSocket support on top
of stdio server, supports blobs
and is tested in CI.

.github/workflows/jsonrpc.yml

@@ -37,9 +37,6 @@ jobs:
         run: npm run test
         env:
           CHATMAIL_DOMAIN: ${{ vars.CHATMAIL_DOMAIN }}
-      - name: make sure websocket server version still builds
-        working-directory: deltachat-jsonrpc
-        run: cargo build --bin deltachat-jsonrpc-server --features webserver
       - name: Run linter
         working-directory: deltachat-jsonrpc/typescript
         run: npm run prettier:check