Snapshot releases (#789)

* A workflow that enables snapshot releases by manual github action

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

* typo in comment

* match naming and add name to workflow

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

.github/workflows/publish-snapshot.yml

@@ -0,0 +1,26 @@
+name: '[CI] Publish Snapshot'
+# Copy /unstable/ to /snapshots/2022.09.1.RC1/
+
+on:
+    workflow_dispatch:
+        inputs:
+            snapshot_version:
+                description: 'The calver version of this snapshot: 2022.09.1 or 2022.09.1.RC1'
+                type: string
+                required: true
+
+jobs:
+    snapshot:
+        runs-on: ubuntu-latest
+        permissions:
+            contents: read
+            id-token: write
+        steps:
+        -   name: Configure AWS credentials
+            uses: aws-actions/configure-aws-credentials@v1.6.1
+            with:
+                aws-region: ${{ secrets.AWS_REGION }}
+                role-to-assume: ${{ secrets.AWS_OIDC_RUNNER_ROLE }}
+        -   name: Sync to S3
+            run: >
+                aws s3 sync --dryrun s3://pyscript.net/unstable/ s3://pyscript.net/snapshots/${{ inputs.snapshot_version }}/