tools: update paths in v8_external_snapshot.gypi
Update the paths to source files in v8_external_snapshot.gypi this was broken and went unnoticed since this target is never really built by default.
Fixes: https://github.com/nodejs/node/issues/28964
Checklist
-
make -j4 test
(UNIX), orvcbuild test
(Windows) passes -
tests and/or benchmarks are included -
documentation is changed or added -
commit message follows commit guidelines
/cc @refack @gengjiawen
I'm not sure how relevant this is and if CI can even check for this. Maybe we should consider just removing this target at some point?