Log Message:
libva: update to 2.18.0.

version 2.18.0 - 19.Mar.2022
* doc: Add build and install libva informatio in home page.
* fix: NULL check before calling strncmp.
* ci: add dependabot
* va: fix the codying style of CHECK_DISPLAY
* va: remove dummy isValid() hook
* x11: use LIBVA_DRI3_DISABLE in GetNumCandidates
* win: compat_win32: Add getenv wrapper for WIN32
* win(WSL): va_drm_utils: Map d3d12 gallium driver for Windows Subsytem for Linux
* fix: Add libva.def into distribution package
* x11: allow disabling DRI3 via LIBVA_DRI3_DISABLe env var
* ci: enable Werror across the build
* win: explicitly ignore CloseAdapter return value
* win: use wide string literal where needed
* win: Add vaDisplayIsValid to .def export list
* va: Always build with va-messaging API
* meson: docs: use libva_version over project_version()
* ci: add github pages workflow
* meson: docs: add encoder interface for av1
* va: add VAProfileH264High10
* fix: Remove reference to non-existent symbol
* va: va/sysdeps.h: remove Android section
* va: remove Android pre Jelly Bean workarounds
* va: remove unused drm_sarea.h include & ANDROID references in va_dricommon.h