I never cease to be amazed at the power of context in translation. So many times I will see what I think is a good translation of a verse; but when I read it in context, red flags start to wave. Phil 4:13 is one of those passages.
All major translations other than the NIV (2011) translate the plural πάντα as a plural. “I can do all things through him who strengthens me” (ESV, so also NASB, NRSV, HCSB, KJV, NET). The 1984 NIV and NLT say, “ I can do everything,” which is essence says the same thing as the plural.