Bump loader-utils and next

[dependabot[bot]]

Removes loader-utils. It's no longer used after updating ancestor dependency next. These dependencies need to be updated together.

Removes loader-utils

Updates next from 12.0.8 to 12.3.4

Commits

• e2c5952 v12.3.4
• 4006812 Update experimental skipTrailingSlashRedirect handling
• be75d09 v12.3.3
• 623622f Update swc builds
• 0381cf0 Add missing matcher support
• b9c7408 Apply normalize patch
• 1b8ab4e Apply middleware patches
• 58dcf30 Apply fix(stream): Allows body larger than 16 KiB with middleware
• f3fc912 v12.3.2
• 3e0f0d6 lock docker image
• Additional commits viewable in compare view

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