feat(subtitles) drop disableStartForAll config option

It wasn't related to transcriptions but to subtitles, really.

Since we are not going to show subtitles just because transcriptions are
enabled, this setting no longer makes sense.

config.js

@@ -413,9 +413,6 @@ var config = {
     //     // ./src/react/features/transcribing/transcriber-langs.json.
     //     preferredLanguage: 'en-US',
 
-    //     // Disable start transcription for all participants.
-    //     disableStartForAll: false,
-
     //     // Enables automatic turning on transcribing when recording is started
     //     autoTranscribeOnRecord: false,
     // },

react/features/base/config/configType.ts

@@ -594,7 +594,6 @@ export interface IConfig {
     transcribingEnabled?: boolean;
     transcription?: {
         autoTranscribeOnRecord?: boolean;
-        disableStartForAll?: boolean;
         enabled?: boolean;
         preferredLanguage?: string;
         translationLanguages?: Array<string>;

react/features/transcribing/middleware.ts

@@ -4,7 +4,6 @@ import {
     PARTICIPANT_UPDATED
 } from '../base/participants/actionTypes';
 import MiddlewareRegistry from '../base/redux/MiddlewareRegistry';
-import { toggleRequestingSubtitles } from '../subtitles/actions.any';
 
 import {
     _TRANSCRIBER_JOINED,
@@ -32,30 +31,14 @@ MiddlewareRegistry.register(({ dispatch, getState }) => next => action => {
     } = getState()['features/transcribing'];
 
     switch (action.type) {
-    case _TRANSCRIBER_JOINED: {
+    case _TRANSCRIBER_JOINED:
         notifyTranscribingStatusChanged(true);
 
-        const state = getState();
-        const { transcription } = state['features/base/config'];
-        const { _requestingSubtitles } = state['features/subtitles'];
-
-        if (!_requestingSubtitles && !transcription?.disableStartForAll) {
-            dispatch(toggleRequestingSubtitles());
-        }
         break;
-    }
-    case _TRANSCRIBER_LEFT: {
+    case _TRANSCRIBER_LEFT:
         notifyTranscribingStatusChanged(false);
 
-        const state = getState();
-        const { transcription } = state['features/base/config'];
-        const { _requestingSubtitles } = state['features/subtitles'];
-
-        if (_requestingSubtitles && !transcription?.disableStartForAll) {
-            dispatch(toggleRequestingSubtitles());
-        }
         break;
-    }
     case HIDDEN_PARTICIPANT_JOINED:
         if (action.displayName === TRANSCRIBER_DISPLAY_NAME) {
             dispatch(transcriberJoined(action.id));