Revert "build sdist with python 3.13 (point to workflow fork) (spacetelescope#9106)"

This reverts commit 72f99a5.

Author: braingram

.github/workflows/changelog.yml

@@ -20,7 +20,7 @@ jobs:
     steps:
       - uses: actions/setup-python@0b93645e9fea7318ecaed2b359559ac225c90a2b  # v5.3.0
         with:
-          python-version: 3.12
+          python-version: 3
       - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683  # v4.2.2
         with:
           fetch-depth: 0