data,apt/release,distro_info,new: replace lazy_static with LazyLock

Unify the lazily-initialized statics on std::sync::LazyLock, which the
newer code already uses: the embed_data! macro expands to a plain
static now, which also removes the visibility-forwarding workaround the
lazy_static! matcher forced on it (the @expand arm wrapping vis in
parentheses), and the 'static ref' spelling is kept at the call sites.
distro_info's HTTP client, the apt keyring cache and the new-template
registry follow the same pattern.

src/apt/release.rs

@@ -45,7 +45,6 @@
 //! keyserver responses are armored) are dearmored in-process, so no `gpg`
 //! binary is needed.
 
-use lazy_static::lazy_static;
 use log::{debug, warn};
 use serde::Deserialize;
 use std::collections::HashMap;
@@ -53,6 +52,7 @@ use std::error::Error;
 use std::fmt;
 use std::path::Path;
 use std::path::PathBuf;
+use std::sync::LazyLock;
 use std::sync::Mutex;
 use std::sync::PoisonError;
 
@@ -793,11 +793,10 @@ async fn fetch_optional(url: &str) -> Option<Vec<u8>> {
     None
 }
 
-lazy_static! {
-    /// Downloaded keyrings, keyed by URL: keyrings are small but would
-    /// otherwise be re-downloaded once per series/pocket lookup
-    static ref KEYRING_CACHE: Mutex<HashMap<String, Vec<u8>>> = Mutex::new(HashMap::new());
-}
+/// Downloaded keyrings, keyed by URL: keyrings are small but would
+/// otherwise be re-downloaded once per series/pocket lookup
+static KEYRING_CACHE: LazyLock<Mutex<HashMap<String, Vec<u8>>>> =
+    LazyLock::new(|| Mutex::new(HashMap::new()));
 
 /// Read the keyring cache, ignoring poisoning (the map is only corrupted on
 /// panics, in which case a fresh map is just as good)