Update loglan-core requirement from ~=0.2 to ~=0.3

Updates the requirements on [loglan-core](https://github.com/torrua/loglan_core) to permit the latest version.
- [Release notes](https://github.com/torrua/loglan_core/releases)
- [Commits](torrua/loglan_core@0.2.0...0.3.0)

---
updated-dependencies:
- dependency-name: loglan-core
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

app/requirements.txt

@@ -1,6 +1,6 @@
 Flask[async]~=3.0
 psycopg2-binary~=2.9
 SQLAlchemy~=2.0
-Loglan-Core~=0.2
+Loglan-Core~=0.3
 aiohttp~=3.10
 waitress~=3.0