Add problem matchers for Yapf and other programs

Add problem matchers for gcc, pytest, and yapf. These programs are used
in CI.

Author: mhucka

.github/problem-matchers/README.md

@@ -6,5 +6,26 @@ This directory contains Problem Matchers used by the GitHub Actions workflows in
 
 The following problem matcher JSON files found in this directory were copied from the [Home Assistant](https://github.com/home-assistant/core) project on GitHub. The Home Assistant project is licensed under the Apache 2.0 open-source license. The version of the files at the time they were copied was 2025.1.2.
 
-- [`pylint.json`](https://github.com/home-assistant/core/blob/dev/.github/workflows/matchers/pylint.json)
-- [`yamllint.json`](https://github.com/home-assistant/core/blob/dev/.github/workflows/matchers/yamllint.json)
+*   [`pylint.json`](https://github.com/home-assistant/core/blob/dev/.github/workflows/matchers/pylint.json)
+*   [`yamllint.json`](https://github.com/home-assistant/core/blob/dev/.github/workflows/matchers/yamllint.json)
+
+The Pytest problem matcher originally came from the
+[gh-problem-matcher-wrap](https://github.com/liskin/gh-problem-matcher-wrap/tree/master/problem-matchers)
+repository (copied 2025-03-04, version 3.0.0), and was subsequently modified by
+Michael Hucka. The original JSON file is Copyright © 2020 Tomáš Janoušek and
+made available under the terms of the MIT license.
+
+*   [`pytest.json`](https://github.com/liskin/gh-problem-matcher-wrap/blob/master/problem-matchers/pytest.json)
+
+The following problem matcher for gcc came from the [Microsoft
+vscode-cpptools](https://github.com/microsoft/vscode-cpptools) repository as it appeared on
+2025-12-04. The last commit was by user michelleangela on 2020-01-09. The file is licensed under the
+MIT license.
+
+*   [`gcc.json`](https://github.com/microsoft/vscode-cpptools/blob/acdd5ca9d21cb1dda535594bee461beb9e8a5f06/Extension/package.json)
+
+The following problem matcher for yapf came from the [Google
+SCAAML](https://github.com/google/scaaml) repository as it appeared on 2025-12-08. The last commit
+was by user jmichelp on 2022-07-03. The file is licensed under the Apache 2.0 license.
+
+*   [`yapf.json`](https://github.com/google/scaaml/blob/6d9c3a42c527212ef77f2877419dd8f6e77eb442/.github/python_matcher.json)

.github/problem-matchers/gcc.json

@@ -0,0 +1,17 @@
+{
+  "problemMatcher": [
+    {
+      "owner": "gcc",
+      "pattern": [
+        {
+          "regexp": "^(.*):(\\d+):(\\d+):\\s+(?:fatal\\s+)?(warning|error):\\s+(.*)$",
+          "file": 1,
+          "line": 2,
+          "column": 3,
+          "severity": 4,
+          "message": 5
+        }
+      ]
+    }
+  ]
+}

.github/problem-matchers/pytest.json

@@ -0,0 +1,16 @@
+{
+  "problemMatcher": [
+    {
+      "owner": "pytest",
+      "severity": "error",
+      "pattern": [
+        {
+          "regexp": "^(\\S+):(\\d+): (.*)$",
+          "file": 1,
+          "line": 2,
+          "message": 3
+        }
+      ]
+    }
+  ]
+}

.github/problem-matchers/yapf.json

@@ -0,0 +1,22 @@
+{
+  "problemMatcher": [
+    {
+      "owner": "yapf-diff",
+      "pattern": [
+        {
+          "regexp": "^---\\s*([^\\s]*)\\s*\\(original\\)$",
+          "file": 1
+        },
+        {
+          "regexp": "^\\+\\+\\+\\s*([^\\s]*)\\s*\\((.*)\\)$",
+          "message": 2
+        },
+        {
+          "regexp": "^@@\\s*-(\\d+),(\\d+)\\s*\\+(\\d+),(\\d+)\\s*@@$",
+          "line": 1
+        }
+      ]
+    },
+  }
+  ]
+}