CI - update GitHub actions to node20

[pavoljuhas]

Bump up to actions/stale@v9 compatible with node20 per
https://github.com/actions/stale/releases/tag/v9.0.0

Related to #6445

[pavoljuhas]

NTS - submit for review once all workflows are checked for old actions.

[codecov]

Codecov Report

Attention: 1 lines in your changes are missing coverage. Please review.

Comparison is base (f2c6f3c) 97.81% compared to head (58b9e3b) 97.81%.
Report is 8 commits behind head on main.

❗ Current head 58b9e3b differs from pull request most recent head b46213a. Consider uploading reports for the commit b46213a to get more accurate results

Files	Patch %	Lines
cirq-core/cirq/experiments/two_qubit_xeb.py	98.86%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #6450      +/-   ##
==========================================
- Coverage   97.81%   97.81%   -0.01%     
==========================================
  Files        1111     1115       +4     
  Lines       97198    97337     +139     
==========================================
+ Hits        95078    95208     +130     
- Misses       2120     2129       +9     

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[NoureldinYosri]

why is there a diff here? as far as I can see there are no changes to this line.

[pavoljuhas]

vim by default fixes up missing newline at the end of file. Proper text files should end in a newline,
otherwise cat f1.txt f2.txt will have strange result.

$ git diff -U0 HEAD^2
diff --git a/.github/workflows/stale.yml b/.github/workflows/stale.yml
index c840eb08..dd7cb263 100644
--- a/.github/workflows/stale.yml
+++ b/.github/workflows/stale.yml
@@ -10 +10 @@ jobs:
-    - uses: actions/stale@v3
+    - uses: actions/stale@v9
@@ -18 +18 @@ jobs:
-        exempt-issue-labels: 'triage/accepted,triage/discuss,kind/design-issue,kind/health,kind/roadmap-item,kind/task'
\ No newline at end of file
+        exempt-issue-labels: 'triage/accepted,triage/discuss,kind/design-issue,kind/health,kind/roadmap-item,kind/task'