event::Caps::caps does not use the EventRef's lifetime

event::Caps::caps no longer returns a CapsRef copying the EventRef's lifetime, making for worse code.

The following code compiles using 0.17, but not 0.18:

use gstreamer::{self as gst, prelude::*};

fn probe_func(_pad: &gst::Pad, info: &mut gst::PadProbeInfo) -> gst::PadProbeReturn {
    let caps = match &info.data {
        Some(gst::PadProbeData::Event(e)) => match e.view() {
            gst::EventView::Caps(c) => c.caps(),
            _ => return gst::PadProbeReturn::Ok,
        },
        _ => unreachable!(),
    };

    println!("{}", caps);

    gst::PadProbeReturn::Ok
}

fn main() {
    gst::init().unwrap();

    let pad = gst::Pad::new(None, gst::PadDirection::Src);
    pad.add_probe(gst::PadProbeType::EVENT_DOWNSTREAM, probe_func);
}

0.18 requires either taking a ref of the caps:

    let caps = match &info.data {
        Some(gst::PadProbeData::Event(e)) => match e.view() {
            gst::EventView::Caps(c) => c.caps_owned(), // 💡 Returns an owned Caps
            _ => return gst::PadProbeReturn::Ok,
        },
        _ => unreachable!(),
    };

    println!("{}", caps);

Or storing the event::Caps first:

    let caps = match &info.data {
        Some(gst::PadProbeData::Event(e)) => match e.view() {
            gst::EventView::Caps(c) => c, // 💡 Extract the event::Caps
            _ => return gst::PadProbeReturn::Ok,
        },
        _ => unreachable!(),
    };

    let caps = caps.caps(); // 💡 Extract the CapsRef

    println!("{}", caps);