🧠 Tweak skipping second search

[eduherminio]

(Already tested PonderHitMinDepthToStopSearch = 5, PonderHitMinTimeToContinueSearch = 50)

PonderHitMinDepthToStopSearch 10 -> 5 (same as original test in #1609)

Finished game 10090 (Lynx 5878 - main vs Lynx-ponder-tweak-skipsecondsearch-5879-win-x64): 1/2-1/2 {Draw by 3-fold repetition}
Score of Lynx-ponder-tweak-skipsecondsearch-5879-win-x64 vs Lynx 5878 - main: 2577 - 2553 - 4960  [0.501] 10090
...      Lynx-ponder-tweak-skipsecondsearch-5879-win-x64 playing White: 2081 - 507 - 2457  [0.656] 5045
...      Lynx-ponder-tweak-skipsecondsearch-5879-win-x64 playing Black: 496 - 2046 - 2503  [0.346] 5045
...      White vs Black: 4127 - 1003 - 4960  [0.655] 10090
Elo difference: 0.8 +/- 4.8, LOS: 63.1 %, DrawRatio: 49.2 %
SPRT: llr -0.332 (-11.5%), lbound -2.25, ubound 2.89

PonderHitMinDepthToStopSearch 10 -> 20

Score of Lynx-ponder-tweak-skipsecondsearch-5879-win-x64 vs Lynx 5878 - main: 275 - 330 - 555  [0.476] 1160
...      Lynx-ponder-tweak-skipsecondsearch-5879-win-x64 playing White: 225 - 69 - 286  [0.634] 580
...      Lynx-ponder-tweak-skipsecondsearch-5879-win-x64 playing Black: 50 - 261 - 269  [0.318] 580
...      White vs Black: 486 - 119 - 555  [0.658] 1160
Elo difference: -16.5 +/- 14.4, LOS: 1.3 %, DrawRatio: 47.8 %
SPRT: llr -0.996 (-34.5%), lbound -2.25, ubound 2.89