Refactor request URL construction for batch sensitivity label assignment

[gautamdsheth]

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Type

• Bug Fix
• New Feature
• Sample

Related Issues?

Fixes #X, partially fixes #Y, mentioned in #Z, etc.

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Please describe the changes in the PR.

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[Copilot]

Pull Request Overview

This pull request refactors URL construction for batch sensitivity label assignment operations by eliminating a helper method and directly constructing URLs inline. The changes simplify the code structure while ensuring proper URL formatting for both batch and non-batch operations.

• Removed the GetRequestUrl helper method and inlined URL construction
• Updated batch request URL format to exclude the "v1.0/" prefix for compatibility
• Simplified JSON serialization by removing custom serializer options

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[Copilot]

Removing the JsonIgnoreCondition.WhenWritingNull option may cause null values to be serialized into the JSON payload, potentially affecting API behavior. Consider whether null properties should be explicitly excluded from the serialized output.

Suggested change

	return JsonSerializer.Serialize(payload);
	var options = new JsonSerializerOptions
	{
	DefaultIgnoreCondition = JsonIgnoreCondition.WhenWritingNull
	};
	return JsonSerializer.Serialize(payload, options);