Fix signing with engine

We need to make sure /run/pcscd/pcscd.comm is available to make
signing work so let's mount /run/pcscd into the sandbox every time
we're going to sign something if it exists.

mkosi/__init__.py

@@ -1497,6 +1497,7 @@ def build_uki(
             ]  # fmt: skip
             if context.config.secure_boot_key_source.type == KeySourceType.engine:
                 cmd += ["--signing-engine", context.config.secure_boot_key_source.source]
+                options += ["--bind-try", "/run/pcscd", "/run/pcscd"]
             if context.config.secure_boot_key.exists():
                 options += ["--ro-bind", context.config.secure_boot_key, context.config.secure_boot_key]
         else:
@@ -1526,6 +1527,7 @@ def build_uki(
                 ]  # fmt: skip
                 options += [
                     "--ro-bind", context.config.secure_boot_certificate, context.config.secure_boot_certificate,  # noqa
+                    "--bind-try", "/run/pcscd", "/run/pcscd",
                 ]  # fmt: skip
 
     cmd += ["build", "--linux", kimg]
@@ -2789,6 +2791,7 @@ def make_image(
     if context.config.verity_key:
         if context.config.verity_key_source.type != KeySourceType.file:
             cmdline += ["--private-key-source", str(context.config.verity_key_source)]
+            options += ["--bind-try", "/run/pcscd", "/run/pcscd"]
         if context.config.verity_key.exists():
             cmdline += ["--private-key", workdir(context.config.verity_key)]
             options += ["--ro-bind", context.config.verity_key, workdir(context.config.verity_key)]

mkosi/bootloader.py

@@ -516,6 +516,7 @@ def sign_efi_binary(context: Context, input: Path, output: Path) -> Path:
         ]  # fmt: skip
         if context.config.secure_boot_key_source.type == KeySourceType.engine:
             cmd += ["--engine", context.config.secure_boot_key_source.source]
+            options += ["--bind-try", "/run/pcscd", "/run/pcscd"]
         if context.config.secure_boot_key.exists():
             cmd += ["--key", workdir(context.config.secure_boot_key)]
             options += ["--ro-bind", context.config.secure_boot_key, workdir(context.config.secure_boot_key)]
@@ -750,6 +751,7 @@ def install_systemd_boot(context: Context) -> None:
                     ]  # fmt: skip
                     if context.config.secure_boot_key_source.type == KeySourceType.engine:
                         cmd += ["--engine", context.config.secure_boot_key_source.source]
+                        options += ["--bind-try", "/run/pcscd", "/run/pcscd"]
                     if context.config.secure_boot_key.exists():
                         cmd += ["--key", workdir(context.config.secure_boot_key)]
                         options += [