[TF2] Fix stickybomb launcher and loose cannon charging sound being delayed by ping

[wgetJane]

demoman is FINALLY playable

this was caused by emitsound being called repeatedly due to prediction/smoothing, which resets the sound over and over so it is audibly delayed

unfixed:

https://github.com/user-attachments/assets/46d23b2f-b884-40e4-b08f-1bb056b78a9f

fixed:

https://github.com/user-attachments/assets/33d36da2-0147-4d39-87d5-bccdb0fb99b1

(i doubt you'd even notice the difference by the first watch of these vids lol, but the difference is noticeable in-game)

partially fixes this issue: https://github.com/ValveSoftware/Source-1-Games/issues/6017

do note that this doesn't fix the charge meter being delayed as you can still see in the videos

im not super sure but as far as i can tell it's caused by subtracting a predicted timestamp (charge begin time) from an unpredicted timestamp (current time when hud is drawn), and it's an issue with like every charge meter hud element

[wgetJane]

i should probably include the fix for the delay on loose cannon's charge sound for this pr as well, which is much more of an important issue for that weapon

edit: tested the same fix but for loose cannon and it does make it feel a LOT better to use