Hide error message and stack for non-error

Avoid printing the error message and stack when we fail to find the
commit. This will happen in several non-error states (e.g.,
when there is no repository checked out at the CWD). Move the
error message to a debug message so that it is still available
if someone really wants to see it.

src/actions-util.ts

@@ -88,9 +88,10 @@ export const getCommitOid = async function (
     return commitOid.trim();
   } catch (e) {
     core.info(
-      `Failed to call git to get current commit. Continuing with data from environment or input: ${e}`
+      "Could not determine current commit SHA. Continuing with data from the environment."
     );
-    core.info((e as Error).stack || "NO STACK");
+    core.debug(`Reason: ${(e as Error).message}`);
+    core.debug((e as Error).stack || "NO STACK");
     return getOptionalInput("sha") || getRequiredEnvParam("GITHUB_SHA");
   }
 };