Update GH issue templates for Linear compatibility (#442)

Author: kahest

.github/ISSUE_TEMPLATE/bug_report.yml

@@ -1,7 +1,6 @@
 name: 🐞 Bug Report
 description: Tell us about something that's not working the way we (probably) intend.
-labels: ["Platform: KMP", "Type: Bug"]
-type: Bug
+labels: ["KMP", "Bug"]
 body:
   - type: dropdown
     id: environment

.github/ISSUE_TEMPLATE/feature.yml

@@ -1,7 +1,6 @@
 name: 💡 Feature Request
 description: Tell us about a problem our SDK could solve but doesn't.
-labels: ["Platform: KMP", "Type: Feature Request"]
-type: Feature
+labels: ["KMP", "Feature"]
 body:
   - type: textarea
     id: problem

.github/ISSUE_TEMPLATE/maintainer-blank.yml

@@ -1,6 +1,6 @@
 name: Blank Issue
 description: Blank Issue. Reserved for maintainers.
-labels: ["Platform: KMP"]
+labels: ["KMP"]
 body:
   - type: textarea
     id: description
@@ -14,4 +14,4 @@ body:
     attributes:
       value: |-
         ## Thanks 🙏
-        Check our [triage docs](https://open.sentry.io/triage/) for what to expect next.
+        Check our [triage docs](https://open.sentry.io/triage/) for what to expect next.