chore: use insta snapshot for blueprint validator tests

crates/aiken-lang/src/parser/expr/snapshots/block_basic.snap

@@ -1,49 +0,0 @@
----
-source: crates/aiken-lang/src/parser/expr/block.rs
-description: "Code:\n\nlet b = {\n  let x = 4\n\n  x + 5\n}\n"
----
-Assignment {
-    location: 0..32,
-    value: Sequence {
-        location: 12..30,
-        expressions: [
-            Assignment {
-                location: 12..21,
-                value: UInt {
-                    location: 20..21,
-                    value: "4",
-                    base: Decimal {
-                        numeric_underscore: false,
-                    },
-                },
-                pattern: Var {
-                    location: 16..17,
-                    name: "x",
-                },
-                kind: Let,
-                annotation: None,
-            },
-            BinOp {
-                location: 25..30,
-                name: AddInt,
-                left: Var {
-                    location: 25..26,
-                    name: "x",
-                },
-                right: UInt {
-                    location: 29..30,
-                    value: "5",
-                    base: Decimal {
-                        numeric_underscore: false,
-                    },
-                },
-            },
-        ],
-    },
-    pattern: Var {
-        location: 4..5,
-        name: "b",
-    },
-    kind: Let,
-    annotation: None,
-}