Move all workflows from app.circleci.com to GH actions

.github/workflows/changelog-checker.yml

@@ -0,0 +1,25 @@
+name: Changelog guard (for release of hotfix)
+
+permissions:
+  contents: read
+
+on:
+  pull_request:
+    branches:
+      - 'release/**'
+      - 'Release/**'
+      - 'hotfix/**'
+      - 'Hotfix/**'
+
+jobs:
+  changelog:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: tj-actions/changed-files@v42
+        id: changed
+      - name: Ensure CHANGELOG.md updated
+        if: contains(steps.changed.outputs.all_changed_files, 'CHANGELOG.md') == false
+        uses: actions/github-script@v7
+        with:
+          script: core.setFailed('CHANGELOG.md must be updated.')

.github/workflows/compatibility.yml

@@ -0,0 +1,27 @@
+name: Requirements compatibility for supported Python versions
+permissions:
+  contents: read
+
+on:
+  pull_request:
+    paths:
+      - "pyproject.toml"
+
+jobs:
+  compatibility:
+    if: github.event.pull_request.draft == false
+    runs-on: ubuntu-latest
+
+    strategy:
+      matrix:
+        python-version: ["3.9", "3.10", "3.11", "3.12", "3.13"]
+
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-python@v5
+        with:
+          python-version: ${{ matrix.python-version }}
+
+      - run: |
+          python -m pip install --upgrade pip
+          python -m pip install ".[dev,cli]" --dry-run --no-deps