fc-common: add unsupported_timeout for queue runner

Hydra maxUnsupportedTime compatibility. DUration is optional, defaults
to `None` and is configurable through `fc.toml` under
`queue_runner.unsupported_timeout` key. E.g., "1h".

Signed-off-by: NotAShelf <raf@notashelf.dev>
Change-Id: I299722e2a3865c873e212a7615b97b806a6a6964

crates/common/Cargo.toml

@@ -14,6 +14,7 @@ clap.workspace               = true
 config.workspace             = true
 git2.workspace               = true
 hex.workspace                = true
+humantime-serde.workspace    = true
 lettre.workspace             = true
 libc.workspace               = true
 regex.workspace              = true