CI: Upgrade from setup-julia@v2 to v3

[DilumAluthge]

No description provided.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 100.00%. Comparing base (a24d034) to head (bfa69ec).

Additional details and impacted files

@@            Coverage Diff            @@
##              main       #52   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files            3         3           
  Lines           64        64           
=========================================
  Hits            64        64           

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[coveralls]

Coverage Report for CI Build 24671754599

Coverage remained the same at 100.0%

Details

• Coverage remained the same as the base build.
• Patch coverage: No coverable lines changed in this PR.
• No coverage regressions found.

Uncovered Changes

No uncovered changes found.

Coverage Regressions

No coverage regressions found.

---

Coverage Stats

Relevant Lines:	64
Covered Lines:	64
Line Coverage:	100.0%
Coverage Strength:	1272.88 hits per line

---

💛 - Coveralls

[DilumAluthge]

CI is all green.

[devmotion]

We want #51, not this PR.