'/execute anchored' applies positional offset for relative (~) coordinates

The bug

When using /execute anchored to change the anchoring context of a command, a positional offset is applied to local coordinates (the ones denoted by carets ^ ^ ^). This offset is also applied to relative coordinates (the ones denoted by tildes ~ ~ ~), which does not match behavior in Java Edition. Attached to this ticket is the same command in both editions.

Steps to reproduce

• Create a new world with the Upcoming Creator Features experiment enabled (or use an existing world).
• Place down a repeating command block, enable the Always Active setting, and enter the following command into it.

  /execute as @p at @s anchored eyes run particle minecraft:basic_flame_particle ~ ~ ~3
  

→ Particle is positioned three blocks south and also at the player's eye height.