🧪🔧 Switch to using pypa/build in CI (#463)

This patch switches the CI/CD workflows to use the PyPA-endorsed
PEP 517 build front-end called `build`. It is called without
`--sdist` and `--wheel` CLI options, in which case `build` creates
an sdist from the Git checkout but the following wheel build is made
from that sdist tarball as opposed to using the Git checkout.

This has a side effect of smoke-testing that it's possible to build
wheels from the published sdists. And this is the flow that
`pip install` follows when it's requested to install from an sdist.

Ref: #460 (comment)

.github/workflows/ci.yml

@@ -32,6 +32,9 @@ jobs:
         with:
           python-version: ${{ matrix.python-version }}
 
+      - name: Install pypa/build
+        run: python -m pip install build==0.10.0
+
       - name: Install Hatch
         run: python -m pip install hatch==1.6.3
 
@@ -74,12 +77,12 @@ jobs:
 
       - name: Build test (gitlint)
         run: |
-          hatch build
+          python -m build
           hatch clean
 
       - name: Build test (gitlint-core)
         run: |
-          hatch build
+          python -m build
           hatch clean
         working-directory: ./gitlint-core
 
@@ -136,4 +139,4 @@ jobs:
     secrets: inherit # pass all secrets (required to access secrets in a called workflow)
     with:
       pypi_target: "pypi.org"
-      repo_release_ref: "main"
+      repo_release_ref: "main"

.github/workflows/publish-release.yml

@@ -43,6 +43,9 @@ jobs:
         with:
           python-version: "3.11"
 
+      - name: Install pypa/build
+        run: python -m pip install build==0.10.0
+
       - name: Install Hatch
         run: python -m pip install hatch==1.6.3
 
@@ -76,13 +79,13 @@ jobs:
           echo "gitlint_version=$(hatch version | cut -d+ -f1)" >> $GITHUB_OUTPUT
 
       - name: Build (gitlint-core)
-        run: hatch build
+        run: python -m build
         working-directory: ./gitlint-core
         env: 
           SETUPTOOLS_SCM_PRETEND_VERSION: ${{ steps.set_version.outputs.gitlint_version }}
 
       - name: Build (gitlint)
-        run: hatch build
+        run: python -m build
         env: 
           SETUPTOOLS_SCM_PRETEND_VERSION: ${{ steps.set_version.outputs.gitlint_version }}