feat(zod)!: drop YAML files support

[Ostrzy]

📋 Description

This PR drops support for YAML files as per @vabatta request, while also removing feature related to them that is JSON parsing values in ENV variables.

The main reason for this change was an edge we've encountered with ENV variables that is string ID consisting of only numbers. When such ID get longs enough, we're getting a number that is bigger than Number.MAX_SAFE_INTEGER, so its value gets altered when parsed as number by JSON.parse.
Example: ENV variable PROJECT_ID="347532342342349855" is turned into number 347532342342349800.

📝 Checklist

• My code follows the project's style guidelines
• I have performed a self-review of my own code
• I have made corresponding changes to the documentation and CI/CD

🚨 Breaking Changes

• Dropped support for YAML configuration files
• ENV variables are no longer parsed as JSON values

Migration Guide

• If you were using YAML configuration files, there's no longer support for them and you have to handle them yourself
• If you were using JSON objects in ENV variables, there's no longer direct support for them and you need to parse them yourself, possibly using zod.transform
• If you relied on numbers / booleans / etc. being parsed by the library, you need to alter your schemas to use z.coerce, so port: z.number().default(5432), turns into port: z.coerce.number().default(5432),

[vabatta]

NICE