fix(render): vendor hayro-postscript so a run of << in a CMap can't overflow the stack (#4363)

hayro-cmap reads CMap streams with hayro-postscript's token scanner,
whose object::read skipped each `<<` and `>>` by calling itself again.
A CMap holding a long run of `<` or `>` used one stack frame per pair,
overflowed the stack and aborted the process.

Vendor hayro-postscript 0.1.0 with read() looping over the delimiters
instead (from storytold/craft-libs#263), patched in beside hayro-cmap.
Four object::tests cover long `<<` and `>>` runs and the skipped
delimiters, plain and nested.

vendor/hayro-postscript/src/error.rs

@@ -0,0 +1,30 @@
+//! Error types for the PostScript scanner.
+
+use core::fmt;
+
+/// A specialized [`Result`] type for PostScript scanner operations.
+pub type Result<T> = core::result::Result<T, Error>;
+
+/// An error encountered while scanning a PostScript token stream.
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub enum Error {
+    /// A syntax error in the input.
+    SyntaxError,
+    /// A numeric value exceeded implementation limits.
+    LimitCheck,
+    /// An unsupported PostScript type was encountered (like dictionaries or
+    /// procedures, which will be added in the future).
+    UnsupportedType,
+}
+
+impl fmt::Display for Error {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            Self::SyntaxError => f.write_str("syntaxerror"),
+            Self::LimitCheck => f.write_str("limitcheck"),
+            Self::UnsupportedType => f.write_str("unsupported type"),
+        }
+    }
+}
+
+impl core::error::Error for Error {}