GitHub workflows: Disable cron schedule for forks (solana-labs#34703)

Forks will run all the cron schedules.  And I do not think they benefit
from those.  For the downstream project checks, these runs are actually
very expensive - about an hour of run time per execution.  Easily
draining free account limits.

.github/workflows/autolock_bot_PR.txt

@@ -14,6 +14,11 @@ concurrency:
 
 jobs:
   action:
+    # Forks do not need to run this, especially on cron schedule.
+    if: >
+      github.event_name != 'schedule'
+      || github.repository == 'solana-labs/solana'
+
     runs-on: ubuntu-latest
     steps:
       - uses: dessant/lock-threads@v3

.github/workflows/autolock_bot_closed_issue.txt

@@ -14,6 +14,11 @@ concurrency:
 
 jobs:
   action:
+    # Forks do not need to run this, especially on cron schedule.
+    if: >
+      github.event_name != 'schedule'
+      || github.repository == 'solana-labs/solana'
+
     runs-on: ubuntu-latest
     steps:
       - uses: dessant/lock-threads@v3

.github/workflows/downstream-project-spl-nightly.yml

@@ -6,6 +6,13 @@ on:
 
 jobs:
   main:
+    # As this is a cron job, it is better to avoid running it for all the forks.
+    # They are unlike to benefit from these executions, and they could easily
+    # eat up all the minutes GitHub allocation to free accounts.
+    if: >
+      github.event_name != 'schedule'
+      || github.repository == 'solana-labs/solana'
+
     strategy:
       fail-fast: false
       matrix:

.github/workflows/manage-stale-issues-and-prs.yml

@@ -17,6 +17,11 @@ permissions:
 
 jobs:
   stale:
+    # Forks do not need to run this, especially on cron schedule.
+    if: >
+      github.event_name != 'schedule'
+      || github.repository == 'solana-labs/solana'
+
     runs-on: ubuntu-latest
     steps:
       - uses: actions/stale@v6