vendor libsecret

The libsecret-rs crate is unmaintained, so I'm vendoring it for
now. Bumping the glib version turned out to be enough.

The exact process I used was:
1. Cloning the repository
2. Making changes
3. `cargo build` to ensure it works
4. `cargo package --no-verify` (b/c it tries to build all crates
separately instead of the entire workspace as a whole)
5. `mkdir libsecret/sys -p`
6. `tar --strip-components 1 -C libsecret -xvf ../libsecret-rs/target/package/libsecret-0.6.0.crate`
7. `tar --strip-components 1 -C libsecret/sys -xvf ../libsecret-rs/target/package/libsecret-sys-0.6.0.crate`

Then `Cargo.toml` is modified to ensure the libsecret and its `-sys`
crate build out of my vendored sources.

In the future, if I gain maintainership of the `libsecret` crate, I
could just revert this commit to make it point back to the upstream.

1 files changed, 17 insertions, 0 deletions

diff --git a/libsecret/sys/Gir.toml b/libsecret/sys/Gir.toml
new file mode 100644
index 0000000..772ef3c
--- /dev/null
+++ b/libsecret/sys/Gir.toml
@@ -0,0 +1,17 @@
+[options]
+work_mode = "sys"
+library = "Secret"
+version = "1"
+girs_directories = ["../../gir-files", "../../"]
+min_cfg_version = "0.1"
+external_libraries = [
+   "GLib",
+   "GObject",
+   "Gio",
+]
+
+ignore = [
+   "Secret.MAJOR_VERSION",
+   "Secret.MICRO_VERSION",
+   "Secret.MINOR_VERSION",
+]
\ No newline at end of file