fix(cat-voices): didUpdateWidget can't await async func

[LynxLynxx]

Description

From time to time, an exception was called in didUpdateWidget:

══╡ EXCEPTION CAUGHT BY FLUTTER ╞═══════════════════════════════════════════════════════════════════
The following _Exception was thrown building _CampaignHeroSection
:
Exception: _HeroSectionState.didUpdateWidget() returned a Future.
State.didUpdateWidget() must be a void method without an `async` keyword.
Rather than awaiting on asynchronous work directly inside of didUpdateWidget, call a separate method
to do this work without awaiting it.

This pr should fix it.

Please confirm the following checks

• My code follows the style guidelines of this project
• I have performed a self-review of my code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream module

[github-actions]

✅ Test Report | ${\color{lightgreen}Pass: 443/443}$ | ${\color{red}Fail: 0/443}$ |

[github-actions]

✅ Test Report | ${\color{lightgreen}Pass: 443/443}$ | ${\color{red}Fail: 0/443}$ |

[dtscalac]

LGTM

[github-actions]

✅ Test Report | ${\color{lightgreen}Pass: 443/443}$ | ${\color{red}Fail: 0/443}$ |