feat(ir): use petgraph

Cargo.lock

@@ -342,6 +342,12 @@ dependencies = [
  "windows-sys 0.59.0",
 ]
 
+[[package]]
+name = "fixedbitset"
+version = "0.5.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1d674e81391d1e1ab681a28d99df07927c6d4aa5b027d7da16ba32d1d21ecd99"
+
 [[package]]
 name = "foldhash"
 version = "0.1.5"
@@ -495,6 +501,7 @@ dependencies = [
  "hashbrown 0.15.3",
  "itertools",
  "lru",
+ "petgraph",
  "priority-queue",
  "regex",
  "replace_with",
@@ -503,6 +510,18 @@ dependencies = [
  "thiserror",
 ]
 
+[[package]]
+name = "petgraph"
+version = "0.8.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "54acf3a685220b533e437e264e4d932cfbdc4cc7ec0cd232ed73c08d03b8a7ca"
+dependencies = [
+ "fixedbitset",
+ "hashbrown 0.15.3",
+ "indexmap",
+ "serde",
+]
+
 [[package]]
 name = "priority-queue"
 version = "2.5.0"