Update doc about $db->select()

[Tigrov]

Merge it before release 2.0

Q	A
Is bugfix?	❌
New feature?	❌
Breaks BC?	❌
Fixed issues

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 98.99%. Comparing base (bfd18e2) to head (2aa289b).

Additional details and impacted files

@@            Coverage Diff            @@
##             master     #987   +/-   ##
=========================================
  Coverage     98.99%   98.99%           
  Complexity     1654     1654           
=========================================
  Files            99       99           
  Lines          4169     4169           
=========================================
  Hits           4127     4127           
  Misses           42       42           

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[Copilot]

Pull Request Overview

This PR updates tests and documentation to use the new $db->select() method instead of instantiating queries with new Query($db), and removes now-unnecessary use Yiisoft\Db\Query\Query imports.

• Replace all new Query($db) calls with $db->select().
• Remove redundant use Yiisoft\Db\Query\Query statements from tests.
• Update code examples in docs and README to match the new API.

Reviewed Changes

Copilot reviewed 19 out of 19 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
tests/Db/Query/QueryTest.php	Switched query instantiation to $db->select()
tests/Db/Expression/StructuredExpressionBuilderTest.php	Updated expression builder test to use $db->select()
tests/Db/Expression/JsonExpressionBuilderTest.php	Updated expression builder test to use $db->select()
tests/Db/Expression/ArrayExpressionBuilderTest.php	Updated expression builder test to use $db->select()
tests/Common/CommonCommandTest.php	Replaced new Query($db) with $db->select() in assertions
tests/AbstractConnectionTest.php	Updated batch query result creation to use $db->select()
src/Query/QueryInterface.php	Updated doc example to use $db->select()
docs/guide/pt-BR/query/with-query.md	Changed example to use $db->select()
docs/guide/pt-BR/query/where.md	Changed example to use $db->select()
docs/guide/pt-BR/query/union.md	Changed example to use $db->select()
docs/guide/pt-BR/query/select.md	Changed example to use $db->select()
docs/guide/pt-BR/query-builder.md	Changed example to use $db->select()
docs/guide/en/schema/typecasting.md	Changed example to use $db->select()
docs/guide/en/query/with-query.md	Changed example to use $db->select()
docs/guide/en/query/where.md	Changed example to use $db->select()
docs/guide/en/query/union.md	Changed example to use $db->select()
docs/guide/en/query/select.md	Changed example to use $db->select()
docs/guide/en/query-builder.md	Changed example to use $db->select()
README.md	Updated sample usage to use $db->select()