Bug - NumberInput: values/validation status not announced to assistive tech on update

Describe the problem
Followup to #7806. Relevant comment chains: https://github.com/patternfly/patternfly-react/pull/7806#pullrequestreview-1077847330, https://github.com/patternfly/patternfly-react/pull/7806#pullrequestreview-1077854208, and https://github.com/patternfly/patternfly-react/pull/7806#issuecomment-1220611457

How do you reproduce the problem?

1. Go to Number input

2. Turn on VoiceOver or another screen reader

3. Use keyboard to update the input (either via the +/- buttons or within the input itself)

4. Notice the value does not get announced

   • In Chromium browsers, updating via buttons or via the input itself does not trigger an announcement. In Firefox and Safari, updating via the input announces the new value but updating via the buttons does not.

Expected behavior
The new value of the input and/or the validation status is announced to assistive tech

Is this issue blocking you?
N/A

Screenshots
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What is your environment?
N/A

What is your product and what release date are you targeting?
N/A

Any other information?
N/A

Jira Issue: PF-174

Commencez par le composant Number input à l’adresse https://www.patternfly.org/v4/components/number-input et examinez la discussion liée dans PR #7806 ainsi que ses commentaires. Reproduisez les mises à jour avec VoiceOver ou un autre lecteur d’écran dans Chromium, Firefox et Safari, puis vérifiez que les changements de valeur et/ou de validation sont annoncés aussi bien pour les mises à jour effectuées avec les boutons que pour les saisies directes.