fix(config): pass logLevel to rolldown during config bundling (fix #21971)

[cyphercodes]

This PR fixes issue #21971 where resolveConfig({ logLevel: 'silent' }) was not suppressing Rolldown warnings during config file bundling.

Problem

When using resolveConfig({ logLevel: 'silent' }), Rolldown warnings were still being displayed during the config file bundling process. This happened because the logLevel option was not being passed to the rolldown() call in bundleConfigFile.

Solution

• Modified bundleConfigFile to accept an optional logLevel parameter
• Modified bundleAndLoadConfigFile to accept and forward logLevel
• Updated the call site in loadConfigFromFile to pass logLevel to the bundler
• The logLevel is now passed directly to the rolldown() call, which respects the 'silent' setting

Changes

• packages/vite/src/node/config.ts: Added logLevel parameter to bundleConfigFile and bundleAndLoadConfigFile, passed it to the rolldown() call

Tested locally by running the existing config tests - all 63 tests pass.