Remove executable bit from CI files

This will prevent generating unneeded dependencies
on things like python.

rust-cxx.spec

@@ -111,6 +111,8 @@ use the "std" feature of the "%{crate}" crate.
 %prep
 %autosetup -n %{crate}-%{version_no_tilde} -p1
 %cargo_prep
+# Remove executable bit from CI tools
+find book/ tools/ -type f -executable -exec chmod a-x '{}' +
 
 %generate_buildrequires
 %cargo_generate_buildrequires