fix: replace from_utf8_unchecked with from_utf8_lossy in SqliteError (#4202)

sqlite3_errmsg() returns UTF-8 in practice but the spec does not
guarantee it. Using from_utf8_unchecked is unsound if non-UTF-8
bytes are returned (e.g. from malformed schema element names).

Closes #4193

Author: joaquinhuigomez

sqlx-sqlite/src/error.rs

@@ -39,7 +39,7 @@ impl SqliteError {
             let msg = sqlite3_errmsg(handle);
             debug_assert!(!msg.is_null());
 
-            str::from_utf8_unchecked(CStr::from_ptr(msg).to_bytes()).to_owned()
+            String::from_utf8_lossy(CStr::from_ptr(msg).to_bytes()).into_owned()
         };
 
         Some(Self {