chore: add SPDX license identifiers

cosmic-applet-audio/Cargo.toml

@@ -2,8 +2,7 @@
 name = "cosmic-applet-audio"
 version = "0.1.1"
 edition = "2021"
-
-# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+license = "GPL-3.0"
 
 [dependencies]
 cosmic-time.workspace = true

cosmic-applet-audio/src/config.rs

@@ -1,3 +1,6 @@
+// Copyright 2023 System76 <info@system76.com>
+// SPDX-License-Identifier: GPL-3.0-only
+
 use cosmic::cosmic_config::cosmic_config_derive::CosmicConfigEntry;
 use cosmic::cosmic_config::{self, CosmicConfigEntry};
 use serde::{Deserialize, Serialize};

cosmic-applet-audio/src/lib.rs

@@ -1,3 +1,6 @@
+// Copyright 2023 System76 <info@system76.com>
+// SPDX-License-Identifier: GPL-3.0-only
+
 mod localize;
 
 use crate::localize::localize;

cosmic-applet-audio/src/localize.rs

@@ -1,4 +1,5 @@
-// SPDX-License-Identifier: MPL-2.0-only
+// Copyright 2023 System76 <info@system76.com>
+// SPDX-License-Identifier: GPL-3.0-only
 
 use cosmic_time::once_cell::sync::Lazy;
 use i18n_embed::{

cosmic-applet-audio/src/main.rs

@@ -1,3 +1,6 @@
+// Copyright 2023 System76 <info@system76.com>
+// SPDX-License-Identifier: GPL-3.0-only
+
 const VERSION: &str = env!("CARGO_PKG_VERSION");
 
 pub fn main() -> cosmic::iced::Result {

cosmic-applet-audio/src/mpris_subscription.rs

@@ -1,3 +1,6 @@
+// Copyright 2023 System76 <info@system76.com>
+// SPDX-License-Identifier: GPL-3.0-only
+
 use std::{borrow::Cow, fmt::Debug, hash::Hash, path::PathBuf};
 
 use cosmic::{

cosmic-applet-audio/src/pulse.rs

@@ -1,3 +1,6 @@
+// Copyright 2023 System76 <info@system76.com>
+// SPDX-License-Identifier: GPL-3.0-only
+
 use std::cell::RefCell;
 use std::{rc::Rc, thread};