style: configure deno fmt to use single quotes

- Add singleQuote: true to deno.json fmt configuration
- Reformat all files with single quotes using deno fmt

test/test.ts

@@ -1,4 +1,4 @@
-import { assert, assertEquals, assertExists } from "jsr:@std/assert@^1.0.0";
+import { assert, assertEquals, assertExists } from 'jsr:@std/assert@^1.0.0';
 import { NupstSnmp } from '../ts/snmp/manager.ts';
 import type { ISnmpConfig } from '../ts/snmp/types.ts';
 
@@ -32,7 +32,7 @@ Deno.test('Real UPS test v1', async () => {
     // Use a short timeout for testing
     const testSnmpConfig = {
       ...snmpConfig,
-      timeout: Math.min(snmpConfig.timeout, 10000) // Use at most 10 seconds for testing
+      timeout: Math.min(snmpConfig.timeout, 10000), // Use at most 10 seconds for testing
     };
 
     // Try to get the UPS status
@@ -69,7 +69,7 @@ Deno.test('Real UPS test v3', async () => {
     // Use a short timeout for testing
     const testSnmpConfig = {
       ...snmpConfig,
-      timeout: Math.min(snmpConfig.timeout, 10000) // Use at most 10 seconds for testing
+      timeout: Math.min(snmpConfig.timeout, 10000), // Use at most 10 seconds for testing
     };
 
     // Try to get the UPS status