function skewY(a, b, u, v) {
  // eslint-disable-next-line no-bitwise
  return `skewY(${((a + (b - a) * v) * 1000 >> 0) / 1000}${u})`;
}
SkewY Interpolation Function.

@param {number} a start angle
@param {number} b end angle
@param {string} u unit, usually `deg` degrees
@param {number} v progress
@returns {string} the interpolated skewY