fix: ...those pesky workflow targets

Signed-off-by: Christina Sørensen <ces@fem.gg>

.github/workflows/unit-tests.yml

@@ -1,15 +1,11 @@
 # SPDX-FileCopyrightText: 2024 Christina Sørensen
 # SPDX-License-Identifier: EUPL-1.2
-#
-# SPDX-FileCopyrightText: 2023-2024 Christina Sørensen, eza contributors
-# SPDX-FileCopyrightText: 2014 Benjamin Sago
-# SPDX-License-Identifier: MIT
 name: Unit tests
 on:
   push:
-    branches: [main]
   pull_request:
-    branches: [main]
+  workflow_dispatch:
+
 concurrency:
   group: ${{ github.workflow }}-${{ github.event_name == 'pull_request' && github.head_ref || github.sha }}
   cancel-in-progress: true