Make vite a peer dependency

[cpulvermacher]

Greetings from Kyushu, and thank you for making this package!

This PR fixes two issues:

• Compatibility with vite 6 and 7. The plugin itself is already working as expected with vite 6+, so this only requires listing the never versions in package.json.
• Having vite in the dependencies can cause npm to install a second, conflicting copy of vite, which can be very hard to debug. For example, installing vite-plugin-handlebars on a project with vite 7 produces:

$ npm ls vite
...
├─┬ @yoichiro/vite-plugin-handlebars@1.4.0
│ └── vite@5.4.21
└── vite@7.3.1

Configuring it in peerDependencies will prioritize the version specified in the root project:

$ npm ls vite
...
├─┬ @yoichiro/vite-plugin-handlebars@1.4.0 (git+ssh://git@github.com/cpulvermacher/vite-plugin-handlebars.git#5b0ff3cca4310c3bcc11ca2fe60c2b1c8bf72214)
│ └── vite@7.3.1 deduped

If the version is incompatible, it will show an error instead of quietly installing an incompatible version. E.g. with vite 4 on the root project:

$ npm install
...
npm error While resolving: @yoichiro/vite-plugin-handlebars@1.4.0
npm error Found: vite@4.5.14
npm error node_modules/vite
npm error   dev vite@"^4.2.4" from the root project
npm error
npm error Could not resolve dependency:
npm error peer vite@"^5.0.0 || ^6.0.0 || ^7.0.0" from @yoichiro/vite-plugin-handlebars@1.4.0

[cpulvermacher]

I've created a temporary fork of the package here https://github.com/cpulvermacher/vite-plugin-handlebars that includes this PR and some version updates.
Will deprecate the package if this one is updated again.