feat: updated rider sdk to 2026.1.0.1

[MikitaY]

Description:

Fixes #561 (#561)

Updated the Rider plugin to be compatible with JetBrains Rider 2026.1 by addressing breaking changes in the SDK and build tooling.

Changes made:

• Updated JetBrains.Rider.SDK to 2026.1.0.1
• Updated Gradle wrapper to 9.4.1
• Updated intellij-platform Gradle plugin to 2.5.0
• Updated Kotlin to 2.1.10
• Fixed SubmenuBehavior usage — constructor became private, replaced with SubmenuBehavior.Custom()
• Removed [NotNull]/[CanBeNull] annotations from JetBrains.Annotations which became inaccessible in the new SDK
• Fixed deprecated toLowerCase() → lowercase() in protocol/build.gradle.kts
• Fixed project.exec {} → providers.exec {} for Gradle 9 compatibility
• Fixed Rider dependency declaration: rider(version) { useInstaller = false }
• Fixed platform type from "riderRD" to "RD"

Tested on:

• Rider 2026.1
• .NET Framework 4.7.2

Checklist:

• I have commented my code, particularly in hard-to-understand areas
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• I have tested my changes by running the extension in VS2017
• I have tested my changes by running the extension in VS2019
• I have tested my changes by running the extension in VS2022
• If changes to the documentation are needed, I have noted this in the description above

[MikitaY]

Compiled version of the plugin for testing:
xamlstyler.rider-0.0.1338.zip

[MikitaY]

Corrected Pipeline:
build-extension-rider-public.yaml