rakudo-star: add test

Closes #28741.

Signed-off-by: Adam Vandenberg <flangy@gmail.com>
tesseract: updated language data

Closes #28731.

Signed-off-by: Adam Vandenberg <flangy@gmail.com>
plt-racket: use enable-macprefix switch

Closes #27291.
Start pointing some things at githubusercontent domain
Use githubusercontent domain