Revert "ot-info: Update after API break in HarfBuzz"

This reverts commit 4901fb74b3c1137d13a6b7e4e8784577c1816e47.

The removed API was added back to HarfBuzz.  So, no need for this.
Revert "build: Require Harfbuzz 0.9.29"

This reverts commit e728c4c3659cc0ead406344b4cf98c0676cb769e.

See previous commit for explanation.