fix: make a json dict for the GitHub outputs

GitHub supports dynamic outputs only if the action use "using: node".
This does not work for "using: composite" or "docker" action.

The workaround is to dump the json into the output.

Then the GitHub workflow will be able to use fromJSON to read it:

```
if: fromJSON(steps.action.outputs.scopes).everything
```

Change-Id: I294c5f828801ad06a6ed613a127ed1b9315e40aa

Author: sileht

mergify_cli/ci/scopes/cli.py

@@ -1,5 +1,6 @@
 from __future__ import annotations
 
+import json
 import os
 import pathlib
 import typing
@@ -17,6 +18,8 @@
 if typing.TYPE_CHECKING:
     from collections import abc
 
+GITHUB_ACTIONS_OUTPUT_NAME = "scopes"
+
 
 def match_scopes(
     files: abc.Iterable[str],
@@ -57,9 +60,8 @@ def maybe_write_github_outputs(
     if not gha:
         return
     with pathlib.Path(gha).open("a", encoding="utf-8") as fh:
-        for key in sorted(all_scopes):
-            val = "true" if key in scopes_hit else "false"
-            fh.write(f"{key}={val}\n")
+        data = {key: key in scopes_hit for key in sorted(all_scopes)}
+        fh.write(f"{GITHUB_ACTIONS_OUTPUT_NAME}={json.dumps(data)}")
 
 
 class InvalidDetectedScopeError(exceptions.ScopesError):

mergify_cli/tests/ci/scopes/test_cli.py

@@ -289,9 +289,7 @@ def test_maybe_write_github_outputs(
     cli.maybe_write_github_outputs(all_scopes, scopes_hit)
 
     content = output_file.read_text()
-    assert "backend=true\n" in content
-    assert "docs=true\n" in content
-    assert "frontend=false\n" in content
+    assert content == """scopes={"backend": true, "docs": true, "frontend": false}"""
 
 
 def test_maybe_write_github_outputs_no_env(