⬆️ Update eslint to v9 / flat config

[BenoitZugmeyer]

Motivation

Keep dependencies up to date

Changes

See Migrate to v9.x

ESLint v9 uses a new configuration format called flat config. The main change was to update to that new configuration.

ESLint now reports unused directive by default. This can be disabled, but I think this is interesting so I kept it and cleaned some unused directives.

Testing

• Local
• Staging
• Unit
• End to end

---

I have gone over the contributing documentation.

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 93.65%. Comparing base (e263716) to head (f8e46fc).
Report is 7 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3259      +/-   ##
==========================================
+ Coverage   93.51%   93.65%   +0.14%     
==========================================
  Files         288      288              
  Lines        7599     7600       +1     
  Branches     1730     1730              
==========================================
+ Hits         7106     7118      +12     
+ Misses        493      482      -11     

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[cit-pr-commenter]

Bundles Sizes Evolution

📦 Bundle Name	Base Size	Local Size	𝚫	𝚫%	Status
Rum	0 B	144.58 KiB	144.58 KiB	N/A%	✅
Logs	0 B	51.09 KiB	51.09 KiB	N/A%	✅
Rum Slim	0 B	103.42 KiB	103.42 KiB	N/A%	✅
Worker	0 B	24.50 KiB	24.50 KiB	N/A%	✅

🚀 CPU Performance

Action Name	Base Average Cpu Time (ms)	Local Average Cpu Time (ms)	𝚫
addglobalcontext	N/A	0.002	0.002
addaction	N/A	0.044	0.044
addtiming	N/A	0.001	0.001
adderror	N/A	0.063	0.063
startstopsessionreplayrecording	N/A	0.009	0.009
startview	N/A	0.368	0.368
logmessage	N/A	0.021	0.021

🧠 Memory Performance

Action Name	Base Consumption Memory (bytes)	Local Consumption Memory (bytes)	𝚫 (bytes)
addglobalcontext	NaN KiB	27.90 KiB	NaN KiB
addaction	NaN KiB	55.72 KiB	NaN KiB
addtiming	NaN KiB	25.40 KiB	NaN KiB
adderror	NaN KiB	58.13 KiB	NaN KiB
startstopsessionreplayrecording	NaN KiB	24.89 KiB	NaN KiB
startview	NaN KiB	414.16 KiB	NaN KiB
logmessage	NaN KiB	58.03 KiB	NaN KiB

🔗 RealWorld