wgpu backend: Enable WebGL fallback (#8038)

* Fix for https://github.com/emilk/eframe_template/issues/223
* Related: https://github.com/gfx-rs/wgpu/pull/9319

By default, we would only turn on the WebGPU backend on web, which means
browsers without WebGPU support would just crash.

You can still opt-out of all the default `wgpu` features by enabling
`eframe/wgpu_no_default_features` instead of `eframe/wgpu`

crates/egui_demo_app/Cargo.toml

@@ -37,7 +37,7 @@ serde = ["dep:serde", "egui_demo_lib/serde", "egui/serde"]
 syntect = ["egui_demo_lib/syntect"]
 
 glow = ["eframe/glow"]
-wgpu = ["eframe/wgpu", "bytemuck", "dep:wgpu"]
+wgpu = ["eframe/wgpu", "bytemuck"]
 wayland = ["eframe/wayland"]
 x11 = ["eframe/x11"]
 
@@ -60,9 +60,6 @@ accesskit_consumer = { workspace = true, optional = true }
 bytemuck = { workspace = true, optional = true }
 puffin = { workspace = true, optional = true }
 puffin_http = { workspace = true, optional = true }
-# Enable both WebGL & WebGPU when targeting the web (these features have no effect when not targeting wasm32)
-# Also enable the default features so we have a supported backend for every platform.
-wgpu = { workspace = true, features = ["default", "webgpu", "webgl"], optional = true }
 
 
 # feature "http":

crates/egui_demo_app/src/backend_panel.rs

@@ -211,7 +211,7 @@ fn integration_ui(ui: &mut egui::Ui, _frame: &mut eframe::Frame) {
         let wgpu_adapter_details_ui = |ui: &mut egui::Ui, adapter: &eframe::wgpu::Adapter| {
             let info = &adapter.get_info();
 
-            let wgpu::AdapterInfo {
+            let eframe::wgpu::AdapterInfo {
                 name,
                 vendor,
                 device,