Log Message:
vala: updated to 0.15.16

Vala 0.56.16
============
 * Various improvements and bug fixes:
  - girparser: Recognize usage of time_t and don't rely on given GIR type
  - girparser: Recognize usage of off_t and don't rely on given GIR type
 * Bindings:
  - gio-2.0: Restore ApplicationCommandLine.print*_literal() to not require 2.80
  - gmodule-2.0: Do not mark `Module.open` as deprecated
  - gtk4: Preserve compatibility with < 4.14
  - Regenerate for GIR-based bindings to pick up time_t fix (long vs time_t)