Workflows: Add automated Release of JSON schema

This adds a GitHub action that implements automated deployment (to the
GitHub Releases section) for the JSON schema file.

It is deployed to the release section because some projects want to
depend on the file as a specification of the IFEX Core IDL.

But since the JSON schema is a generated artifact based on the internal
model defined in the source code (ifex_ast.py), it should not be
committed to the source code repository, since there can be a risk of
mismatch.  Therefore it is generated.

Note: It is set up to create a release, and a tag, by inserting
a line like this in the commit:

Signed-off-by: Gunnar Andersson <[email protected]>

.github/workflows/create-new-release.yml

@@ -0,0 +1,80 @@
+# Workflow to create a new release when RELEASE-TAG is included in commit.
+#
+# Preconditions:
+# 1) The tag that is determined from the commit message must not already exist
+# 2) The workflow does not work if pushing an existing tag.  
+# 3) The precondition ensures this workflow is NOT run if no RELEASE-TAG field.
+#
+# Action steps:
+# 1) Commit and add the RELEASE-TAG in message
+# 2) Tag locally with the tag
+#   DO NOT PUSH THE TAG
+# 3) Push commit (possibly via a pull request)
+# 4) When pushed or merge to master, the release process will create the remote tag and the release
+
+name: Deploy JSON Schema and create release
+
+on:
+  push:
+    branches:
+      - master
+
+jobs:
+  deploy_json_schema:
+    if: "contains(github.event.head_commit.message, 'RELEASE-TAG')"
+    runs-on: ubuntu-22.04
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Setup Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: 3.12.3
+
+      - name: Install dependencies
+        run: |
+          python -V
+          pip install -r requirements.txt
+
+      - name: Install IFEX module
+        run: python setup.py develop
+
+      - name: Run JSON-Schema generator
+        run: |
+          python ifex/schema/ifex_to_json_schema.py >temp-schema
+          python ifex/schema/pretty_print_json.py temp-schema >ifex-core-idl-schema.json
+
+      - name: Determine variables
+        run: |
+          echo "TAG=$(echo "${{ github.event.head_commit.message }}" | grep -E '^ *RELEASE-TAG' | awk '{print $2}')"  >> "$GITHUB_OUTPUT"
+          echo "HASH=$(git rev-parse HEAD | cut -c 1-16)" >> "$GITHUB_OUTPUT"
+          echo "SHORTHASH=$(git rev-parse HEAD | cut -c 1-10)" >> "$GITHUB_OUTPUT"
+        id: vars
+
+      - name: Create Release of JSON Schema file
+        if: "contains(github.event.head_commit.message, 'RELEASE-TAG')"
+        uses: actions/create-release@v1
+        id: create_release
+        with:
+          draft: false
+          prerelease: false
+          release_name: "JSON schema for ${{ steps.vars.outputs.TAG }}"
+          tag_name: "${{ steps.vars.outputs.TAG }}"
+          body: |
+            The JSON Schema file for the IFEX Core IDL is a resulting artifact, generated from the internal model representation.
+            This one was generated from commit hash ${{ steps.vars.outputs.HASH }} and was assigned the release-name: ${{ steps.vars.outputs.TAG }}."
+        env:
+          GITHUB_TOKEN: "${{ github.token }}"
+
+      - name: Upload Release Asset
+        if: "contains(github.event.head_commit.message, 'RELEASE-TAG')"
+        id: upload-release-asset
+        uses: actions/upload-release-asset@v1
+        with:
+          upload_url: ${{ steps.create_release.outputs.upload_url }} # Defined by previous step
+          asset_path: ./ifex-core-idl-schema.json
+          asset_name: ifex-core-idl-schema.json
+          asset_content_type: application/json
+        env:
+          GITHUB_TOKEN: "${{ secrets.GITHUB_TOKEN }}"
+