[sm-1253] Updating dotnet version (#894)

## 🎟️ Tracking

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point to where this change is coming from. -->

## 📔 Objective

Manually updating the .net version for the c# sdk, renovate had these
updates disabled.

## 📸 Screenshots

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width images for better display. -->

## ⏰ Reminders before review

- Contributor guidelines followed
- All formatters and local linters executed and passed
- Written new unit and / or integration tests where applicable
- Protected functional changes with optionality (feature flags)
- Used internationalization (i18n) for all UI strings
- CI builds passed
- Communicated to DevOps any deployment requirements
- Updated any necessary documentation (Confluence, contributing docs) or
informed the documentation
  team

## 🦮 Reviewer guidelines

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- 👍 (`:+1:`) or similar for great changes
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- 🤔 (`:thinking:`) or 💭 (`:thought_balloon:`) for more open inquiry
that's not quite a confirmed
  issue and could potentially benefit from discussion
- 🎨 (`:art:`) for suggestions / improvements
- ❌ (`:x:`) or ⚠️ (`:warning:`) for more significant problems or
concerns needing attention
- 🌱 (`:seedling:`) or ♻️ (`:recycle:`) for future improvements or
indications of technical debt
- ⛏ (`:pick:`) for minor or nitpick changes

languages/csharp/global.json

@@ -1,6 +1,6 @@
 {
   "sdk": {
-    "version": "6.0.100",
+    "version": "8.0.100",
     "rollForward": "latestFeature"
   }
 }