Update http and switch to json_schema

[buraktabn]

json_schema2 is discontinued. It's recommended to replace with json_schema.

[CLAassistant]

All committers have signed the CLA.

[codecov]

Codecov Report

Attention: Patch coverage is 50.00000% with 4 lines in your changes missing coverage. Please review.

Project coverage is 48.48%. Comparing base (591782e) to head (152f4aa).
Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
...bstrate_metadata/lib/utils/spec_version_maker.dart	50.00%	4 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #498   +/-   ##
=======================================
  Coverage   48.48%   48.48%           
=======================================
  Files         181      181           
  Lines        9588     9592    +4     
=======================================
+ Hits         4649     4651    +2     
- Misses       4939     4941    +2     

Flag	Coverage Δ
polkadart	15.89% <ø> (ø)
polkadart_cli	12.04% <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	87.66% <50.00%> (-0.07%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files with missing lines	Coverage Δ
...bstrate_metadata/lib/utils/spec_version_maker.dart	41.66% <50.00%> (+1.04%)	⬆️

---- 🚨 Try these New Features:

• Flaky Tests Detection - Detect and resolve failed and flaky tests

[leonardocustodio]

Lgtm, thank you for the contribution

[leonardocustodio]

@all-contributors please add @buraktabn for code

[allcontributors]

@leonardocustodio

I've put up a pull request to add @buraktabn! 🎉