To expand a bit on what dmertz said, the tax rate on long-term capital gain is determined by your taxable income, not gross income. Taxable income is your Adjusted Gross Income (AGI) minus your standard deduction or itemized deductions. For 2022, the standard deduction is $12,950 if you file as single, you cannot be claimed as a dependent, and you are under 65 and not blind. So if your gross income, including the long-term capital gain, is $46,000, your taxable income will be $46,000 - $12,950 = $33,050. That is well below the $41,675 limit for the zero percent rate on long-term capital gain, even without any IRA contribution.
