Update minSdkVersion to 24 and remove deprecated code

[rfc2822]

Purpose

Update the minimum SDK version to Android 7 (API 24) and remove deprecated compatibility code that is no longer needed.

Short description

• Update minSdk from 23 to 24 in lib/build.gradle.kts
• Replace deprecated closeCompat() calls with standard close() in 11 test files
• Remove the closeCompat() compatibility method from MiscUtils.kt

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