What is the relationship between System.IdentityModel and Microsoft.Data.SqlClient?

Question

I'm using old code for JWT validation, and the reference to System.IdentityModel throws an error unless I add the Microsoft.Data.SqlClient dependency.

I would like to know why this happens.

private string generateJwtToken(Employee employee)
{
    var tokenHandler = new System.IdentityModel.Tokens.Jwt.JwtSecurityTokenHandler();
    var key = System.Text.Encoding.ASCII.GetBytes(secret);
    var symmetricKey = new Microsoft.IdentityModel.Tokens.SymmetricSecurityKey(key);
    var claimRe = new System.Security.Claims.Claim("re", employee.re.ToString());
    var claimRl = new System.Security.Claims.Claim("role", employee.role.ToString());
    var claims = new[] { claimRe, claimRl };

    var tokenDescriptor = new Microsoft.IdentityModel.Tokens.SecurityTokenDescriptor
    {
        Subject = new System.Security.Claims.ClaimsIdentity(claims),
        Expires = DateTime.UtcNow.AddDays(7),
        SigningCredentials = new Microsoft.IdentityModel.Tokens.SigningCredentials(symmetricKey, Microsoft.IdentityModel.Tokens.SecurityAlgorithms.HmacSha256Signature)
    };

    var token = tokenHandler.CreateToken(tokenDescriptor);
    return tokenHandler.WriteToken(token);
}

Note: code from when I was studying.