check: Change runner image to ubuntu-24.04; add step to install sys…

…tem dependency

Change the runner image to use `ubuntu-24.04` directly, because
`ubuntu-latest` may cause CI failures when there are unexpected changes
in the future versions of the runner image.

Then also add a step to manually install the `libsqlite3-dev` package,
which we need.

The `package:sqlite3` requires the system-installed sqlite3 shared
library (`libsqlite3.so`) when running directly via Dart, on Linux.
Whereas, when running under Flutter, it uses bundled libraries provided
by `package:sqlite3_flutter_libs`.

Previously, with `ubuntu-22.04` the `libsqlite3-dev` package was
pre-installed:
  https://github.com/actions/runner-images/blob/main/images/ubuntu/Ubuntu2204-Readme.md#installed-apt-packages
However, the `ubuntu-24.04` image no longer includes this package by
default:
  https://github.com/actions/runner-images/blob/main/images/ubuntu/Ubuntu2404-Readme.md#installed-apt-packages

Without that package, five unit tests would fail with the following
error:
  Invalid argument(s): Failed to load dynamic library 'libsqlite3.so': libsqlite3.so: cannot open shared object file: No such file or directory
    dart:ffi                                                        new DynamicLibrary.open
    package:sqlite3/src/ffi/load_library.dart 52:27                 _defaultOpen
    package:sqlite3/src/ffi/load_library.dart 127:12                OpenDynamicLibrary.openSqlite
    package:sqlite3/src/ffi/api.dart 13:39                          sqlite3
    package:drift/native.dart 313:12                                _NativeDelegate.openDatabase
    package:drift/src/sqlite3/database.dart 79:19                   Sqlite3Delegate.open
    package:drift/src/runtime/executor/helpers/engines.dart 431:22  DelegatedDatabase.ensureOpen.<fn>

.github/workflows/ci.yml

@@ -4,10 +4,13 @@ on: [push, pull_request]
 
 jobs:
   check:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-24.04
     steps:
     - uses: actions/[email protected]
 
+    - name: Install system dependencies
+      run: TERM=dumb sudo apt install libsqlite3-dev -y
+
     - name: Set up JDK
       uses: actions/[email protected]
       with: