Bump fable from 5.0.0-alpha.17 to 5.0.0-alpha.19

---
updated-dependencies:
- dependency-name: fable
  dependency-version: 5.0.0-alpha.19
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

.config/dotnet-tools.json

@@ -10,7 +10,7 @@
       "rollForward": false
     },
     "fable": {
-      "version": "5.0.0-alpha.17",
+      "version": "5.0.0-alpha.19",
       "commands": [
         "fable"
       ],