In config.sh, change directory before running `ldd ./bin/libcoreclr.so`.

[jonpugh]

I'm doing a crazy thing with the runner. I'm adding it as a composer bin script, which symlinks it to vendor/bin dir.

The config.sh script can be run this way, except for the "Check dotnet Core 6.0 dependencies for Linux".

This is because it calls ldd ./bin/x using relative paths when pwd might be different.

Moving the cd code to run before the ldd checks fixes it.