Don't block on snippet evaluation

If a snippet is evaluated with runCustomREPLCommand and it blocks (due
to a bug or some such) then the editor almost completely deadlocks.

This commit changes the command handler for `runCustomREPLCommand` to
not block on snippet evaluation.

Fixes BetterThanTomorrow#2012

CHANGELOG.md

@@ -4,6 +4,8 @@ Changes to Calva.
 
 ## [Unreleased]
 
+- Fix: [Evaluating blocking snippets deadlocks the editor](https://github.com/BetterThanTomorrow/calva/issues/2012)
+
 ## [2.0.323] - 2023-01-07
 
 - Fix: [Provider completions not handling errors gracefully](https://github.com/BetterThanTomorrow/calva/issues/2006)

src/custom-snippets.ts

@@ -20,7 +20,9 @@ type SnippetDefinition = {
 export async function evaluateCustomCodeSnippetCommand(
   codeOrKeyOrSnippet?: string | SnippetDefinition
 ) {
-  await evaluateCodeOrKeyOrSnippet(codeOrKeyOrSnippet);
+  evaluateCodeOrKeyOrSnippet(codeOrKeyOrSnippet).catch((err) => {
+    console.log('Failed to run snippet', err);
+  });
 }
 
 async function evaluateCodeOrKeyOrSnippet(codeOrKeyOrSnippet?: string | SnippetDefinition) {