fix: next function is not available for pre middlewares in mongoose 9

[abnud11]

When trying to upgrade Mongoose in our app to 9, we faced this error:

TypeError: next is not a function

That's because Mongoose 9 no longer passes next to pre middlewares; instead, you either throw an error or do nothing.

This PR attempts to fix the error while still passing the tests.

[Copilot]

Pull request overview

This PR upgrades the mongoose-delete plugin to support Mongoose 9.x while maintaining backward compatibility with versions 5-8. The main change addresses Mongoose 9's removal of the next callback parameter from pre middlewares by conditionally checking if next is a function before calling it.

• Adds Mongoose 9.x to peer dependencies
• Updates dev dependency to Mongoose ^9.0.0
• Fixes pre('save') middleware to work with both old and new Mongoose versions

Reviewed changes

Copilot reviewed 2 out of 3 changed files in this pull request and generated no comments.

File	Description
package.json	Adds Mongoose 9.x to peer dependencies and updates dev dependency to ^9.0.0
package-lock.json	Updates dependency tree with Mongoose 9.0.0 and its transitive dependencies (mongodb 7.0.0, kareem 3.0.0, etc.)
index.js	Adds conditional check for next function in pre('save') middleware to support Mongoose 9's removal of callback parameter, plus code formatting improvements

Comments suppressed due to low confidence (3)

index.js:347

• This expression assigns variable conditions to itself.

        callback = adjustCallbackForMongooseVersion(callback);

index.js:211

• This negation always evaluates to true.

                    schema.statics[method + 'Deleted'] = function () {

index.js:217

• This negation always evaluates to true.

                    };

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[abnud11]

@dsanel Can we review this PR please? it's necessary for mongoose 9 support

[dsanel]

@abnud11 thx. Added an extra commit [164d644] to add additional check.