Log Message:
vala: updated to 0.56.15

Vala 0.56.15
============
 * Various improvements and bug fixes:
  - codegen:
    + Use GWeakRef for [SingleInstance] constructors
    + Remove static mutex initialization
    + Correctly return FALSE on uncaught error in async ctor
    + Cast generic return value from g_ptr_array_index()
    + Don't use pre-assigned *_parent_iface field if an instance is given
    + Emit diagnostic pragmas for GCC 14, Clang 16 compatibility
  - vala:
    + Keep depfile empty if no dependencies were written
    + Treat negative integer/float ranks as non-compatible
    + Move formal_target_type when transforming method-call/object-creation
    + Follow the logic of GIrParser.locate_gir() to find gir files
  - girparser:
    + Don't blindly translate utf8 to string and check the ctype too
    + Issue a warning for `record` inside `transparent union`
    + Don't discard explictly given ctype of parameters
  - libvaladoc: Fix build with graphviz >= 10.0.1

 * Bindings:
  - glib-2.0,posix: Define _GNU_SOURCE for sincos*()
  - gio-2.0: Fix pointer-sign errors of some uint8[]-typed paramters
  - gio-2.0,gmodule-2.0: Update from 2.79.x git
  - gmodule-2.0: Improvements and updates from 2.76
  - gtk4: Fix GLib.Value parameter in Expression.evaluate()
  - gtk4: Update to 4.13.9~f46fb7c6
  - libsoup-3.0: Don't skip uri_copy
  - v4l2: Fix FrameivalEnum.stepwise type mismatch with v4l2_frmivalenum