cd(push-to-discord.yaml): update message push to use cUrl

.github/workflows/push-to-discord.yaml

@@ -17,9 +17,8 @@ jobs:
         uses: actions/[email protected]
 
       - name: Post Discord
-        env:
-          DISCORD_WEBHOOK: $ {{ secrets.GDSC_CAU_DISCORD_ARTICLES }}
-          DISCORD_EMBEDS: '[{ "author": { "name": "${{ github.event.pull_request.user.login }}" }, "title": "${{ github.event.pull_request.title }}", "description": "${{ github.event.pull_request.body }}", "color": "${{ vars.DISCORD_EMBED_COLOR }}" }]'
-        uses: Ilshidur/[email protected]
-        with:
-          args: "New readings are updated!"
+        run: |
+          curl -X POST \
+            -H "Content-Type: application/json" \
+            -d '{ "content": "New readings are updated!", "embeds": [{ "author": { "name": "${{ github.event.pull_request.user.login }}" }, "title": "${{ github.event.pull_request.title }}", "url": "https://github.com/${{ github.repository }}", "description": "${{ github.event.pull_request.body }}", "color": ${{ vars.DISCORD_EMBED_COLOR }} }]}' \
+            $ {{ secrets.GDSC_CAU_DISCORD_ARTICLES }}