fix(web): prevents warning that occurs when multitapping longpressable modifier keys

[jahorton]

Fixes: #12963

User Testing

TEST_NAIJATYPE_CAPS_ON_ANDROID: Using Keyman for Android..

1. Double-tap on the default-layer shift key and verify that:
   • No error or warning messages appear
   • The CAPS layer activates and holds, even after typing a couple of letters
2. Triple-tap the default layer i key, verifying that ị results and that no errors or warnings occur.

TEST_EUROLATIN: Using Keyman for Android, verify that the keyboard's caps-lock behavior works properly.

[keymanapp-test-bot]

User Test Results

Test specification and instructions

• ✅ TEST_NAIJATYPE_CAPS_ON_ANDROID (PASSED) (notes)
• ✅ TEST_EUROLATIN (PASSED) (notes)

Test Artifacts

• Android
  • Keyman for Android apk
  • FirstVoices for Android 16.0 apk
  • FirstVoices Keyboards for Android apk
  • KeyboardHarness apk
  • Keyman for Android 16.0 apk
  • KMSample1 apk
  • KMSample2 apk
• Developer
  • Keyman Developer
  • Compiler Regression Tests
  • kmcomp.zip
• iOS
  • Keyman for iOS (simulator image)
  • FirstVoices Keyboards for iOS (simulator image)
  • TestFlight internal PR build version - 18.0.173 (0.12964.12647)
• Keyboards
  • Test Keyboards
• Web
  • KeymanWeb Test Home
• Windows
  • Keyman for Windows
  • FirstVoices Keyboards for Windows
  • Text Editor (32 bit)
  • Text Editor (64 bit)

[dinakaranr]

Test Results

I tested this issue with the attached "18.0.173-alpha-test-12964" build(21/01/2025) on Android 14(Physical Device). I'm sharing my observation here.

• TEST_NAIJATYPE_CAPS_ON_ANDROID (Passed):

1. Installed the "Keyman-18.0.173.apk" file from this PR build.
2. Open the Keyman app.
3. Checked the "Enable Keyman as system-wide keyboard". Set the keyboard as the default keyboard box on the settings page.
4. Installed the "NAIJATYPE" keyboard.
5. Navigate to the Keyman edit notepad.
6. Enter some letters using the "naijatype" keyboard.
7. Double tap on the "Shift" key.
8. Verified that no error & warning message appeared.
9. Hold on to any cap key and then select the subkeys.
10. Verified that the subkeys appeared
11. Disable the caps layer by pressing the "Shift key"
12. Triple-tap the default layer " i " key.
13. Verified that no error & warning message appeared.
14. Verified that the " ị " letter appeared.
    It works well.

• TEST_EUROLATIN (Passed):

1. Installed the "Keyman-18.0.173.apk" file from this PR build.
2. Open the Keyman app.
3. Checked the "Enable Keyman as system-wide keyboard". Set the keyboard as the default keyboard box on the settings page.
4. Double tap on the "Shift" key.
5. Verified that no error & warning message appeared.
6. Hold on to any cap key and then select the subkeys.
7. Verified that the subkeys appeared.
   It works well.