changed variable declaration from var to let and const

[Lovelyfin00]

Fixes #1086 (<=== Add issue number here)

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[PeculiarE]

Nicely done! @Lovelyfin00

@jywarren, @TildaDares, @cesswairimu ....kindly help merge this PR. Thank you!

[TildaDares]

Amazing work @Lovelyfin00. Thank you!

[TildaDares]

Thank you for the review @PeculiarE!

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[TildaDares]

Congratulations on merging your PR @Lovelyfin00 🎉