build: Remove workaround for hatchling upgrades

Apparently Dependabot now supports upgrading build-system.requires: we
don't need the workarounds anymore.

Signed-off-by: Jussi Kukkonen <jkukkonen@google.com>

Author: jku

.github/workflows/cd.yml

@@ -33,7 +33,7 @@ jobs:
 
       - name: Build binary wheel, source tarball and changelog
         run: |
-          PIP_CONSTRAINT=requirements/build.txt python3 -m build --sdist --wheel --outdir dist/ .
+          python3 -m build --sdist --wheel --outdir dist/ .
           awk "/## $GITHUB_REF_NAME/{flag=1; next} /## v/{flag=0} flag" docs/CHANGELOG.md > changelog
 
       - name: Store build artifacts

pyproject.toml

@@ -1,8 +1,5 @@
 [build-system]
-# Dependabot cannot do `build-system.requires` (dependabot/dependabot-core#8465)
-# workaround to get reproducibility and auto-updates:
-#   PIP_CONSTRAINT=requirements/build.txt python3 -m build ...
-requires = ["hatchling"]
+requires = ["hatchling==1.27.0"]
 build-backend = "hatchling.build"
 
 [project]

requirements/build.txt

@@ -2,4 +2,3 @@
 # during CI and CD Github workflows
 build==1.2.2.post1
 tox==4.1.2
-hatchling==1.27.0