Use log crate instead of eprintln & remove some unwraps (#5010)

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- I fixed the TODO to use the `log` crate instead of `eprintln`
- Set the rust-version in the `scripts/check.sh` to the same as egui is
on
- I made xtask use anyhow to remove some unwraps 

* [x] I have followed the instructions in the PR template

examples/puffin_profiler/Cargo.toml

@@ -25,5 +25,6 @@ env_logger = { version = "0.10", default-features = false, features = [
     "auto-color",
     "humantime",
 ] }
+log = { workspace = true }
 puffin = "0.19"
 puffin_http = "0.16"

examples/puffin_profiler/src/main.rs

@@ -9,6 +9,8 @@ use std::sync::{
 use eframe::egui;
 
 fn main() -> eframe::Result {
+    let rust_log = std::env::var("RUST_LOG").unwrap_or_else(|_| "info".to_owned());
+    std::env::set_var("RUST_LOG", rust_log);
     env_logger::init(); // Log to stderr (if you run with `RUST_LOG=debug`).
     start_puffin_server(); // NOTE: you may only want to call this if the users specifies some flag or clicks a button!
 
@@ -153,7 +155,7 @@ fn start_puffin_server() {
 
     match puffin_http::Server::new("127.0.0.1:8585") {
         Ok(puffin_server) => {
-            eprintln!("Run:  cargo install puffin_viewer && puffin_viewer --url 127.0.0.1:8585");
+            log::info!("Run:  cargo install puffin_viewer && puffin_viewer --url 127.0.0.1:8585");
 
             std::process::Command::new("puffin_viewer")
                 .arg("--url")
@@ -167,7 +169,7 @@ fn start_puffin_server() {
             std::mem::forget(puffin_server);
         }
         Err(err) => {
-            eprintln!("Failed to start puffin server: {err}");
+            log::error!("Failed to start puffin server: {err}");
         }
     };
 }

examples/serial_windows/Cargo.toml

@@ -20,3 +20,4 @@ env_logger = { version = "0.10", default-features = false, features = [
     "auto-color",
     "humantime",
 ] }
+log = { workspace = true }

examples/serial_windows/src/main.rs

@@ -12,7 +12,7 @@ fn main() -> eframe::Result {
         ..Default::default()
     };
 
-    eprintln!("Starting first window…");
+    log::info!("Starting first window…");
     eframe::run_native(
         "First Window",
         options.clone(),
@@ -21,7 +21,7 @@ fn main() -> eframe::Result {
 
     std::thread::sleep(std::time::Duration::from_secs(2));
 
-    eprintln!("Starting second window…");
+    log::info!("Starting second window…");
     eframe::run_native(
         "Second Window",
         options.clone(),
@@ -30,7 +30,7 @@ fn main() -> eframe::Result {
 
     std::thread::sleep(std::time::Duration::from_secs(2));
 
-    eprintln!("Starting third window…");
+    log::info!("Starting third window…");
     eframe::run_native(
         "Third Window",
         options,
@@ -53,7 +53,7 @@ impl eframe::App for MyApp {
             ui.label(label_text);
 
             if ui.button("Close").clicked() {
-                eprintln!("Pressed Close button");
+                log::info!("Pressed Close button");
                 ui.ctx().send_viewport_cmd(egui::ViewportCommand::Close);
             }
         });