fix: add display warning for mumbai

[sahar-fehri]

Description

This PR adds a display of a deprecation warning when a user switches to MUMBAI network

Related issues

Fixes:

Manual testing steps

1. Go to settings => network => add network => Custom networks
2. Fill in inputs: Name:Mumbai; RPC_URL:https://80001.rpc.thirdweb.com; chainId: 80001; Symbol: MATIC
3. Switch to this network
4. You should be able to see a deprecation warning "This network is deprecated"

Screenshots/Recordings

Before

Screen.Recording.2024-04-03.at.23.33.27.mov

After

Screen.Recording.2024-04-03.at.23.26.45.mov

Pre-merge author checklist

• I’ve followed MetaMask Coding Standards.
• I've completed the PR template to the best of my ability
• I’ve included tests if applicable
• I’ve documented my code using JSDoc format if applicable
• I’ve applied the right labels on the PR (see labeling guidelines). Not required for external contributors.

Pre-merge reviewer checklist

• I've manually tested the PR (e.g. pull and build branch, run the app, test code being changed).
• I confirm that this PR addresses all acceptance criteria described in the ticket it closes and includes the necessary testing evidence such as recordings and or screenshots.

[github-actions]

CLA Signature Action: All authors have signed the CLA. You may need to manually re-run the blocking PR check if it doesn't pass in a few minutes.

[github-actions]

Bitrise

✅✅✅ pr_smoke_e2e_pipeline passed on Bitrise! ✅✅✅

Commit hash: d6b7b05
Build link: https://app.bitrise.io/app/be69d4368ee7e86d/pipelines/298ae0ac-1ee3-4a28-89e9-dbed46fb2fd6

Note

• You can kick off another pr_smoke_e2e_pipeline on Bitrise by removing and re-applying the Run Smoke E2E label on the pull request

[sonarcloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
16.7% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarCloud

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 25.00000% with 3 lines in your changes are missing coverage. Please review.

Project coverage is 46.05%. Comparing base (91f222d) to head (d6b7b05).

Files	Patch %	Lines
app/components/Nav/Main/index.js	0.00%	3 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #9125      +/-   ##
==========================================
- Coverage   46.05%   46.05%   -0.01%     
==========================================
  Files        1273     1273              
  Lines       31274    31278       +4     
  Branches     3195     3195              
==========================================
+ Hits        14404    14405       +1     
- Misses      16027    16030       +3     
  Partials      843      843              

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[MarioAslau]

LGTM !

[metamaskbot]

Missing release label release-7.20.0 on PR. Adding release label release-7.20.0 on PR and removing other release labels(release-7.21.0), as PR was cherry-picked in branch 7.20.0.