Workaround for https://github.com/rust-lang/cargo/issues/10788

[dahlbaek]

As described in Cargo Issue 10788, until Rust 1.71 there were cases where the dependency/feature syntax would not work correctly when used in combination with the dep:dependency syntax. Workarounds include adding an explicit feature

dependency = ["dep:dependency"]

but in many (most?) cases it is enough to only enable the dependency feature if the dependency is already enabled, via the dependency?/feature syntax.

For context, here are some workarounds employed by others:

• https://github.com/mstange/samply/commit/89456d46720217ecd24b451ffdaf358d67d60a1d
• https://github.com/alexrudy/tonic/commit/f3869543f8dd183428c5f476b335e2c5b3032c64
• https://github.com/jwodder/confab/commit/6f0e2fc3ee012a99b44ba9b16415c38de8d495ed

[Seeker14491]

Thanks! With the way I wrote these features, I've now discovered that we were pulling in the dbus crate by default, which is not intended; it's only supposed to be pulled in when enabling the reveal feature. This PR also fixes this regression.