fix: use correct schema dialect for oas3.0.x and oas2.x

[vadyvas]

What/Why/How?

• Updated schema validation flow to select AJV dialect by spec version:
  • oas2 / oas3_0 -> draft-04 (id)
  • oas3_1 / oas3_2 -> 2020-12 ($id)
• Updated schema registration to use the proper schema ID key per dialect.

Reference

• Closes: Lint rules for examples require exclusiveMinimum to be number in openapi 3.0.x #1610
• Related AJV PR: feat: add draft4 support ajv#39

Testing

• Added unit and e2e tests
• Test in Reunite
  • ✅https://github.com/Redocly/redocly/actions/runs/21987248928?pr=20934
  • ✅https://github.com/Redocly/redocly/actions/runs/21987304645?pr=20934

Screenshots (optional)

N/A

Check yourself

• Code changed? - Tested with Redoc/Realm/Reunite (internal)
• All new/updated code is covered by tests
• New package installed? - Tested in different environments (browser/node)
• Documentation update considered

Security

• The security impact of the change has been considered
• Code follows company security practices and guidelines

[changeset-bot]

🦋 Changeset detected

Latest commit: 63b2f13

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 3 packages

Name	Type
@redocly/openapi-core	Patch
@redocly/cli	Patch
@redocly/respect-core	Patch

Not sure what this means? Click here to learn what changesets are.

Click here if you're a maintainer who wants to add another changeset to this PR

[github-actions]

CLI Version	Mean Time ± Std Dev (s)	Relative Performance (Lower is Faster)
cli-latest	3.622s ± 0.026s	▓ 1.00x (Fastest)
cli-next	3.651s ± 0.053s	▓ 1.01x

[github-actions]

Coverage Report

Status	Category	Percentage	Covered / Total
🔵	Lines	79.44% (🎯 78%)	6327 / 7964
🔵	Statements	78.88% (🎯 78%)	6537 / 8287
🔵	Functions	83.35% (🎯 82%)	1297 / 1556
🔵	Branches	71.03% (🎯 70%)	4307 / 6063

File Coverage

File	Stmts	Branches	Functions	Lines	Uncovered Lines
Changed Files
packages/core/src/rules/ajv.ts	93.87%	91.66%	88.88%	97.77%	54, 133
packages/core/src/rules/utils.ts	91.17%	88.88%	100%	90.32%	47, 71, 80-83, 93, 105-108, 189

Generated in workflow #8637 for commit 63b2f13 by the Vitest Coverage Report Action

[github-actions]

📦 A new experimental 🧪 version v0.0.0-snapshot.1770986081 of Redocly CLI has been published for testing.

Install with NPM:

npm install @redocly/cli@0.0.0-snapshot.1770986081
# or
npm install @redocly/openapi-core@0.0.0-snapshot.1770986081
# or
npm install @redocly/respect-core@0.0.0-snapshot.1770986081

⚠️ Note: This is a development build and may contain unstable features.

[tatomyr]

Left minor comments. Otherwise looks good.