test: cover all alternative manifest files for new ecosystems

Expand test_build_dependabot_file_with_new_ecosystems from 15 subtests
to 26 by testing every manifest filename variant, not just the first
one per ecosystem. This covers alternative files like WORKSPACE for
bazel, compose.yaml for docker-compose, .pre-commit.yml for
pre-commit, etc.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: zkoppert

test_dependabot_file.py

@@ -421,26 +421,38 @@ def test_build_dependabot_file_with_gradle(self):
         self.assertEqual(result, expected_result)
 
     def test_build_dependabot_file_with_new_ecosystems(self):
-        """Test that the dependabot.yml file is built correctly for newly added ecosystems"""
-        ecosystems = {
-            "bazel": "MODULE.bazel",
-            "bun": "bun.lock",
-            "conda": "environment.yml",
-            "docker-compose": "docker-compose.yml",
-            "dotnet-sdk": "global.json",
-            "elm": "elm.json",
-            "gitsubmodule": ".gitmodules",
-            "helm": "Chart.yaml",
-            "julia": "Project.toml",
-            "pre-commit": ".pre-commit-config.yaml",
-            "pub": "pubspec.yaml",
-            "rust-toolchain": "rust-toolchain.toml",
-            "swift": "Package.swift",
-            "uv": "uv.lock",
-            "vcpkg": "vcpkg.json",
-        }
-        for ecosystem, manifest_file in ecosystems.items():
-            with self.subTest(ecosystem=ecosystem, manifest_file=manifest_file):
+        """Test that the dependabot.yml file is built correctly for newly added ecosystems.
+        Each (ecosystem, manifest_file) pair gets its own subTest so every
+        alternative manifest filename is verified, not just the first one."""
+        ecosystems = [
+            ("bazel", "MODULE.bazel"),
+            ("bazel", "WORKSPACE"),
+            ("bazel", "WORKSPACE.bazel"),
+            ("bun", "bun.lock"),
+            ("conda", "environment.yml"),
+            ("conda", "environment.yaml"),
+            ("docker-compose", "docker-compose.yml"),
+            ("docker-compose", "docker-compose.yaml"),
+            ("docker-compose", "compose.yaml"),
+            ("docker-compose", "compose.yml"),
+            ("dotnet-sdk", "global.json"),
+            ("elm", "elm.json"),
+            ("gitsubmodule", ".gitmodules"),
+            ("helm", "Chart.yaml"),
+            ("julia", "Project.toml"),
+            ("pre-commit", ".pre-commit-config.yaml"),
+            ("pre-commit", ".pre-commit-config.yml"),
+            ("pre-commit", ".pre-commit.yaml"),
+            ("pre-commit", ".pre-commit.yml"),
+            ("pub", "pubspec.yaml"),
+            ("rust-toolchain", "rust-toolchain.toml"),
+            ("rust-toolchain", "rust-toolchain"),
+            ("swift", "Package.swift"),
+            ("uv", "uv.lock"),
+            ("vcpkg", "vcpkg.json"),
+            ("vcpkg", "vcpkg-configuration.json"),
+        ]
+        for ecosystem, manifest_file in ecosystems:
                 repo = MagicMock()
                 repo.file_contents.side_effect = lambda f, mf=manifest_file: f == mf