Fix: Prevent spellcast errors when shifting to Bear Form as Druid

[Xleone1]

Summary

This pull request fixes a bug for Druids where the /threat macro would result in the classic error message:

"Another action is in progress" (twice)

This happened when the addon attempted to cast Druid threat abilities immediately after triggering Bear Form via CastShapeshiftForm(1). In Vanilla WoW, you cannot cast abilities in the same macro/script call right after shapeshifting, as the form change must complete first.

Changes

• Modified DruidThreat() to return early after casting Bear Form.
• Prevents ability cast attempts until Bear Form is fully active.

Before

if (ActiveStance() ~= 1) then
  Debug("Changing to bear form");
  CastShapeshiftForm(1)
end

-- Fails immediately after form cast
CastSpellByName(ABILITY_MAUL)

After

if (ActiveStance() ~= 1) then
  Debug("Changing to bear form");
  CastShapeshiftForm(1)
  return -- wait until next run to cast threat abilities
end

Result

Druids no longer receive “Another action is in progress” errors. /threat works correctly once already in Bear Form or after shifting finishes.

[Xleone1]

I'm new to working Git and I realized that all the changes I'm making for my own version of the addon are being included in this PR as well. These can be ignored if you don't want to have them in your version of the addon.