Remove rpm package dependencies

This is an attempt to fix Issues #4015 #4008.

Seems like CentOS and Red Hat are not providing `libgnome-keyring` to their official yum repository, and since the spec has `Requires: libgnome-keyring` it doesn't let them install without resolving the dependency.

In this PR, I removed all package dependencies with the assumption that those are all `build dependencies` (including libgnome-keyring) and if they are not installed then the build process (`script/build`) will fail, therefore we can't build rpm yet. In other words, rpm-build does not need to check those dependencies if they are all `build dependencies`.

Thank you.