Prevent GitHub Actions from unintentionally running on forks (#492)

Fixes #413.

Author: miorel

.github/workflows/deploy-github-pages.yml

@@ -24,6 +24,10 @@ concurrency:
 
 jobs:
   deploy-github-pages:
+    # Only run this job on the original repository! To run this on your fork,
+    # update or remove the line below.
+    if: github.repository == 'code-chronicles-code/leetcode-curriculum'
+
     environment:
       name: deploy-github-pages
       url: ${{ steps.deployment.outputs.page_url }}

.github/workflows/post-leetcode-potd-to-discord.yml

@@ -21,6 +21,10 @@ concurrency:
 
 jobs:
   post-leetcode-potd-to-discord:
+    # Only run this job on the original repository! To run this on your fork,
+    # update or remove the line below.
+    if: github.repository == 'code-chronicles-code/leetcode-curriculum'
+
     environment:
       name: post-leetcode-potd-to-discord
 

.github/workflows/update-leetcode-problem-data.yml

@@ -22,6 +22,10 @@ permissions:
 
 jobs:
   update-problem-data:
+    # Only run this job on the original repository! To run this on your fork,
+    # update or remove the line below.
+    if: github.repository == 'code-chronicles-code/leetcode-curriculum'
+
     runs-on: ubuntu-latest
 
     steps: