Use TOML 1.0.0 compliant library for parsing (#47)

iarna/toml is unmaintained.
Replaced by smol-toml which is maintained and has the same api

src/utils/pyproject.ts

@@ -1,15 +1,28 @@
 import * as fs from "node:fs";
 import * as core from "@actions/core";
-import * as toml from "@iarna/toml";
+import * as toml from "smol-toml";
 
 export function getRuffVersionFromPyproject(
   filePath: string,
 ): string | undefined {
+  if (!fs.existsSync(filePath)) {
+    core.warning(`Could not find file: ${filePath}`);
+    return undefined;
+  }
   const pyprojectContent = fs.readFileSync(filePath, "utf-8");
-  const pyproject = toml.parse(pyprojectContent) as {
-    project?: { dependencies?: string[] };
-    "dependency-groups"?: { dev?: string[] };
-  };
+  let pyproject:
+    | {
+        project?: { dependencies?: string[] };
+        "dependency-groups"?: { dev?: string[] };
+      }
+    | undefined;
+  try {
+    pyproject = toml.parse(pyprojectContent);
+  } catch (err) {
+    const message = (err as Error).message;
+    core.warning(`Error while parsing ${filePath}: ${message}`);
+    return undefined;
+  }
 
   const dependencies: string[] = pyproject?.project?.dependencies || [];
   const devDependencies: string[] = pyproject?.["dependency-groups"]?.dev || [];