ci: Do not produce build artifacts when run in a fork (#30294)

If someone forks the `solana` repo, they should not have access to Slack
or AWS storage locations that hold build artifacts.  Meaning, actions
that interact with that infrastructure will always fail.  It makes sense
to disable these actions in forks.

.github/workflows/docs.yml

@@ -68,7 +68,9 @@ jobs:
   build_and_deploy:
     needs:
       - check
-    if: ${{ needs.check.outputs.continue == 1 }}
+    if: >
+      github.repository == 'solana-labs/solana' &&
+      needs.check.outputs.continue == 1
     # the name is used by .mergify.yml as well
     name: build & deploy docs
     runs-on: ubuntu-20.04

.github/workflows/release-artifacts-auto.yml

@@ -14,6 +14,7 @@ concurrency:
 
 jobs:
   release-artifacts:
+    if: github.repository == 'solana-labs/solana'
     uses: ./.github/workflows/release-artifacts.yml
     with:
       commit: ${{ github.sha }}