Log Message:
harfbuzz, harfbuzz-icu: Update to 6.0.0

Changelog:
  * A new API have been added to pre-process the face and speed up future
    subsetting operations on that face. Provides up to a 95% reduction in
    subsetting times when the same face is subset more than once.

    For more details and benchmarks, see:
    https://github.com/harfbuzz/harfbuzz/blob/main/docs/subset-preprocessing.md

    (Garret Rieger, Behdad Esfahbod)

  * Shaping have been speedup by skipping entire lookups when the buffer
    contents don't intersect with the lookup. Shows up to a 10% speedup in
    shaping some fonts. (Behdad Esfahbod)

  * A new experimental feature, Variable Composites (enabled by passing
    -Dexperimental_api=true to meson), is also featured in this release. This
    technology enables drastic compression of fonts in the Chinese, Japanese,
    Korean, and other writing systems, by reusing the OpenType Font Variations
    technology for encoding ??smart components?? into the font.

    The specification for these extensions to the font format can be found in:
    https://github.com/harfbuzz/boring-expansion-spec/blob/glyf1/glyf1.md

    A test variable font with ~7160 Hangul syllables derived from the
    NotoSerifKR-VF font has been built, with existing OpenType technology, as
    well as with the new Variable Composites (VarComposites) technology. The
    VarComposites font is over 90% smaller than the OpenType version of the
    font!

    Both fonts can be obtained from the ??smarties?? repository:
    https://github.com/behdad/smarties/tree/3.0/fonts/hangul/serif

    When building HarfBuzz with experimental features enabled, you can test the
    ??smarties?? font with a sample character like this:

    $ hb-view butchered-hangul-serif-smarties-variable.ttf -u AE01 \ 
--variations=wght=700

    (Behdad Esfahbod)

  * The HarfBuzz subsetter can now drop axes by pinning them to specific values
    (also referred to as instancing). There are a couple of restrictions
    currently:

      + Only works with TrueType (glyf) based fonts. CFF2 fonts are not yet
        supported.
      + Only supports the case where all axes in a font are pinned.

    (Garret Rieger, Qunxin Liu)

  * Miscellaneous fixes and improvements.

    (Behdad Esfahbod, Christoph Reiter, David Corbett, Eli Schwartz, Garret
    Rieger, Joel Auterson, Jordan Petridis, Khaled Hosny, Lorenz Wildberg,
    Marco Rebhan, Martin Storsj?, Matthias Clasen, Qunxin Liu, Satadru
    Pramanik)

  * New API
    +hb_subset_input_pin_axis_location()
    +hb_subset_input_pin_axis_to_default()
    +hb_subset_preprocess()