[BUG] Specifying tap_time for individual keys prevents holdtap keys from tap interrupting each other

[regicidalplutophage]

Describe the bug

holdtap = HoldTap()
holdtap.tap_time = 500

LCTL = KC.HT(KC.F, KC.LCTRL, prefer_hold=True, tap_interrupted=True)
RCTL = KC.HT(KC.J, KC.RCTRL, prefer_hold=True, tap_interrupted=True)

This works like one would think it would.

LCTL = KC.HT(KC.F, KC.LCTRL, prefer_hold=True, tap_interrupted=True, tap_time = 500)
RCTL = KC.HT(KC.J, KC.RCTRL, prefer_hold=True, tap_interrupted=True, tap_time = 500)

This doesn't

To Reproduce

LCTL = KC.HT(KC.F, KC.LCTRL, prefer_hold=True, tap_interrupted=True, tap_time = 500)
RCTL = KC.HT(KC.J, KC.RCTRL, prefer_hold=True, tap_interrupted=True, tap_time = 500)

• Hold RCTL, tap LCTL within tap time.
• The output would be f

Expected behavior
Output should be ctrl+f

Debug output
If applicable, add debug output from the serial console to help explain your problem.

Additional context
This was tested both with master and #740