chore: Bump demaconsulting.spdxtool from 2.5.0 to 2.6.0

---
updated-dependencies:
- dependency-name: demaconsulting.spdxtool
  dependency-version: 2.6.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

.config/dotnet-tools.json

@@ -9,7 +9,7 @@
       ]
     },
     "demaconsulting.spdxtool": {
-      "version": "2.5.0",
+      "version": "2.6.0",
       "commands": [
         "spdx-tool"
       ]