podvm-mkosi: Fix mkosi delete log

We are seeing
```
rm: cannot remove '/usr/local/bin/mkosi': No such file or directory
```
in the log, when the delete fails, so
use `-f`  to ignore file delete if it doesn't exist

Signed-off-by: stevenhorsman <[email protected]>

.github/workflows/podvm_mkosi_image.yaml

@@ -70,7 +70,7 @@ jobs:
       - name: Install mkosi
         run: |
           git clone -b v22 https://github.com/systemd/mkosi
-          sudo rm /usr/local/bin/mkosi | true
+          sudo rm -f /usr/local/bin/mkosi
           sudo ln -s $PWD/mkosi/bin/mkosi /usr/local/bin/mkosi
           mkosi --version