fix abstract introduction sentence

Signed-off-by: Filipe Laíns <lains@riseup.net>

Author: FFY00

pep-9999.rst

@@ -14,7 +14,7 @@ Abstract
 ========
 
 This PEP attempts to document the status of cross-compilation of downstream
-projects, more specifically
+projects.
 
 It should give an overview of the approaches currently used by distributors
 (Linux distros, WASM environment providers, etc.) to cross-compile downstream