[xrefdelta] Fix typos in paper numbers referenced in comments (cplusplus#7165)

Author: Mick235711

source/xrefdelta.tex

@@ -79,13 +79,13 @@
 % https://github.com/cplusplus/draft/pull/6255
 \movedxref{container.gen.reqmts}{container.requirements.general}
 
-% P2875 Undeprecate polymorphic_allocator::destroy
+% P2875R4 Undeprecate polymorphic_allocator::destroy
 \movedxref{depr.mem.poly.allocator.mem}{mem.poly.allocator.mem}
 
 % https://github.com/cplusplus/draft/pull/6653
 \movedxref{mismatch}{alg.mismatch}
 
-% P3400R10 std::execution
+% P2300R10 std::execution
 \movedxref{stopsource.nonmembers}{stopsource}
 \movedxref{stoptoken.cons}{stopsource}
 \movedxref{stoptoken.nonmembers}{stopsource}