firmware/reducers: remove 'flashing' state

The 'flashing' state variable in the firmware reducer is not used
anymore so can be removed.

src/firmware/reducers.test.ts

@@ -2,15 +2,8 @@
 // Copyright (c) 2021-2026 The Pybricks Authors
 
 import { AnyAction } from 'redux';
-import {
-    FailToFinishReasonType,
-    didFailToFinish,
-    didFinish,
-    didStart,
-} from './actions';
-import reducers from './reducers';
 
-type State = ReturnType<typeof reducers>;
+import reducers from './reducers';
 
 test('initial state', () => {
     expect(reducers(undefined, {} as AnyAction)).toMatchInlineSnapshot(`
@@ -18,7 +11,6 @@ test('initial state', () => {
           "dfuWindowsDriverInstallDialog": {
             "isOpen": false,
           },
-          "flashing": false,
           "installPybricksDialog": {
             "isOpen": false,
           },
@@ -31,14 +23,3 @@ test('initial state', () => {
         }
     `);
 });
-
-test('flashing', () => {
-    expect(reducers({ flashing: false } as State, didStart()).flashing).toBe(true);
-    expect(reducers({ flashing: true } as State, didFinish()).flashing).toBe(false);
-    expect(
-        reducers(
-            { flashing: true } as State,
-            didFailToFinish(FailToFinishReasonType.TimedOut),
-        ).flashing,
-    ).toBe(false);
-});

src/firmware/reducers.ts

@@ -3,9 +3,6 @@
 
 import { Reducer, combineReducers } from 'redux';
 import {
-    didFailToFinish,
-    didFinish,
-    didStart,
     firmwareDidFailToFlashUsbDfu,
     firmwareDidFailToRestoreOfficialDfu,
     firmwareDidFailToRestoreOfficialEV3,
@@ -20,18 +17,6 @@ import dfuWindowsDriverInstallDialog from './dfuWindowsDriverInstallDialog/reduc
 import installPybricksDialog from './installPybricksDialog/reducers';
 import restoreOfficialDialog from './restoreOfficialDialog/reducers';
 
-const flashing: Reducer<boolean> = (state = false, action) => {
-    if (didStart.matches(action)) {
-        return true;
-    }
-
-    if (didFinish.matches(action) || didFailToFinish.matches(action)) {
-        return false;
-    }
-
-    return state;
-};
-
 const isFirmwareFlashUsbDfuInProgress: Reducer<boolean> = (state = false, action) => {
     if (firmwareFlashUsbDfu.matches(action)) {
         return true;
@@ -86,7 +71,6 @@ export default combineReducers({
     dfuWindowsDriverInstallDialog,
     installPybricksDialog,
     restoreOfficialDialog,
-    flashing,
     isFirmwareFlashUsbDfuInProgress,
     isFirmwareRestoreOfficialDfuInProgress,
     isFirmwareFlashEV3InProgress,