address PR feedback: bump 0.2.15, drop old snapshots, format slnx

- Bump version 0.2.14 -> 0.2.15 (per @jupblb)
- Remove snapshots/output-net6.0 and snapshots/output-net7.0 (TFMs are dropped)
- Add 'dotnet format --verify-no-changes' step for snapshots/input/syntax-slnx

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

Author: slang25

.github/workflows/test.yml

@@ -21,6 +21,8 @@ jobs:
       - run: dotnet format --verify-no-changes
       - run: dotnet format --verify-no-changes
         working-directory: snapshots/input/syntax
+      - run: dotnet format --verify-no-changes
+        working-directory: snapshots/input/syntax-slnx
   test:
     runs-on: ${{ matrix.os }}
     strategy:

ScipDotnet/ScipDotnet.csproj

@@ -4,7 +4,7 @@
     <OutputType>Exe</OutputType>
     <ImplicitUsings>enable</ImplicitUsings>
     <Nullable>enable</Nullable>
-    <Version>0.2.14</Version>
+    <Version>0.2.15</Version>
     <PackageLicenseFile>LICENSE</PackageLicenseFile>
     <PackageReadmeFile>readme.md</PackageReadmeFile>
     <PackageType>DotnetTool</PackageType>