Run vm startup and shutdown from runner temp dir.

Should work even if the github workspace dir is on a stale sshfs mount.

.github/workflows/selfhosted.yml

@@ -74,6 +74,7 @@ jobs:
     steps:
     - name: shutdown VM if running
       run: vmshutdown
+      working-directory: ${{ runner.temp }}
     - uses: actions/checkout@main
     - name: autoreconf
       run: autoreconf
@@ -106,3 +107,4 @@ jobs:
     - name: shutdown VM
       if: always()
       run: vmshutdown
+      working-directory: ${{ runner.temp }}

.github/workflows/upstream.yml

@@ -20,6 +20,7 @@ jobs:
     - uses: actions/checkout@main
     - name: shutdown VM if running
       run: vmshutdown
+      working-directory: ${{ runner.temp }}
     - name: startup VM
       run: vmstartup
     - name: update source
@@ -45,3 +46,4 @@ jobs:
     - name: shutdown VM
       if: always()
       run: vmshutdown
+      working-directory: ${{ runner.temp }}