deprecate hand_on_thighs and hands_on_thighs

BUR #43107 has been approved by @nonamethanks.

deprecate hand_on_thighs
deprecate hands_on_thighs

Similar to topic #32401, the following tags already exist and are in use that specify who's thigh is being touched. Additionally hand on thigh is already a deprecated tag.

• hand on own thigh
• hand on another's thigh
• hands on own thighs
• hands on another's thigh
• hands on another's thighs

The bulk update request #43107 (forum #363789) has been approved by @nonamethanks.