v1.39.0

• Release: 1.39.0 (ba5e3f3)
• Update: box-annotations to v1.3.0 (#764) (77bb4cc), closes #764
• Update: Issue template (#762) (23a0059), closes #762
• Fix: Add blend mode fallbacks if not supported (#758) (95def3b), closes #758
• Fix: release script (#757) (203e55d), closes #757
• Fix: Remove use of manifest loaded event (#763) (99edac8), closes #763
• Fix: Revert media duration setting to on loadeddata (#759) (df798d1), closes #759