DoS in bigdecimal's sqrt function due to miscalculation of loop iterations

Vulnerability __Affected Product__: `bigdecimal` extension in https://github.com/ruby/ruby __Affected Versions__: At least version 3.2.2, I didn't test any previous versions

do {
    y->MaxPrec *= 2;
    if (y->MaxPrec > y_prec) y->MaxPrec = y_prec;
    f->MaxPrec = y->MaxPrec;
    VpDivd(f, r, x, y);        /* f = x/y    */
    VpAddSub(r, f, y, -1);     /* r = f - y  */
    VpMult(f, VpConstPt5, r);  /* f = 0.5*r  */
    if (VpIsZero(f))
        goto converge; …