Incomplete French (fr) translation: RequiredOptionWasNotProvided not translated

## Description

The French satellite assembly (fr/System.CommandLine.resources.dll) shipped with System.CommandLine 2.0.9 contains untranslated strings.

## Current behavior

When CultureInfo.DefaultThreadCurrentUICulture is set to fr-FR and a required option is missing:

`
Option '--input' is required.
`

## Expected behavior

The message should be in French:

`
L'option '--input' est obligatoire.
`

## Analysis

Inspecting the fr/System.CommandLine.resources.dll satellite assembly shows that RequiredOptionWasNotProvided still holds the English text, along with several other untranslated keys (ArgumentConversionCannotParse, HelpOptionDescription, HelpOptionsRequiredLabel, SuggestionsTokenNotMatched, etc.).

## Environment

- System.CommandLine version: 2.0.9
- .NET version: net10.0

## Suggested fix

Update the French resource file to translate all missing keys, at minimum:
- RequiredOptionWasNotProvided = L'option '{0}' est obligatoire.
- HelpOptionsRequiredLabel = (OBLIGATOIRE)

Start by locating the French resource source that produces fr/System.CommandLine.resources.dll, then inspect the RequiredOptionWasNotProvided and other listed untranslated keys. Translate the missing entries, including the suggested RequiredOptionWasNotProvided and HelpOptionsRequiredLabel values, and rebuild the French satellite assembly. Verify the required-option message under fr-FR and check the other listed keys.

Written by the indexing model from the issue text.