build(php): upgrade min php version to 8.3

.devcontainer/Dockerfile

.gitlab-ci.yml

app/Controllers/BaseController.php

app/Controllers/EpisodeAudioController.php

app/Controllers/PostController.php

app/Controllers/WebmanifestController.php

app/Database/Migrations/2021-05-29-152000_add_categories.php

app/Database/Migrations/2021-05-30-101000_add_languages.php

app/Database/Migrations/2021-05-30-101500_add_podcasts.php

app/Database/Migrations/2021-06-05-170000_add_episodes.php

app/Database/Migrations/2021-06-05-190000_add_platforms.php

...e/Migrations/2021-06-05-200000_add_podcasts_platforms.php

...ase/Migrations/2021-08-12-150000_add_episode_comments.php

app/Database/Migrations/2021-08-12-160000_add_likes.php

app/Database/Migrations/2021-08-17-150000_add_pages.php

.../Migrations/2021-09-29-150000_add_podcasts_categories.php

app/Database/Migrations/2021-12-09-130000_add_clips.php

app/Database/Migrations/2021-12-25-120000_add_persons.php

...ase/Migrations/2021-12-25-130000_add_podcasts_persons.php

...ase/Migrations/2021-12-25-140000_add_episodes_persons.php