Upgrade the lib to work with dart >= 3.3.0

[leonardocustodio]

PR Type

enhancement, documentation

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Description

• Updated the package version in pubspec.yaml from 0.4.6 to 0.4.7.
• Added a changelog entry for version 0.4.7, documenting a fix for the UnmodifiableUint8ListView issue on newer Dart versions.

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Changes walkthrough 📝

	Relevant files
Documentation	CHANGELOG.md Update changelog for version 0.4.7 with recent fixes          packages/polkadart/CHANGELOG.md Added entry for version 0.4.7. Documented fix for UnmodifiableUint8ListView issue on newer Dart versions. +3/-0
Enhancement	pubspec.yaml Bump package version to 0.4.7                                                        packages/polkadart/pubspec.yaml Updated package version from 0.4.6 to 0.4.7. +1/-1

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[github-actions]

PR Reviewer Guide 🔍

⏱️ Estimated effort to review: 1 🔵⚪⚪⚪⚪

🧪 No relevant tests

🔒 No security concerns identified

⚡ No key issues to review

[github-actions]

PR Code Suggestions ✨

No code suggestions found for the PR.

[justkawal]

LGTM

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 48.46%. Comparing base (2b3416c) to head (401a159).
Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #480   +/-   ##
=======================================
  Coverage   48.46%   48.46%           
=======================================
  Files         181      181           
  Lines        9575     9575           
=======================================
  Hits         4641     4641           
  Misses       4934     4934           

Flag	Coverage Δ
polkadart	15.91% <ø> (ø)
polkadart_cli	12.02% <ø> (ø)
polkadart_keyring	65.24% <ø> (ø)
polkadart_scale_codec	54.93% <ø> (ø)
secp256k1_ecdsa	89.60% <ø> (ø)
sr25519	85.91% <ø> (ø)
ss58	96.87% <ø> (ø)
substrate_bip39	56.37% <ø> (ø)
substrate_metadata	87.72% <ø> (ø)

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