refactor: Improve Code Readability and Maintainability

In this commit, I've made the following enhancements to the code:
1. Replaced the magic value 17 with meaning constant for clarity.
2. Instead of directly checking the disabledTimeItems.length to be 2, make sure whether it's really the value we assigned (17 or 5pm).
3. Split the test-cases and move the test-case for checking the aria-disabled attribute to a separate it block.

Closes Hacker0x01#4334

test/filter_times_test.test.js

@@ -4,15 +4,43 @@ import { getHours } from "../src/date_utils";
 import TimeComponent from "../src/time";
 
 describe("TimeComponent", () => {
+  const HOUR_TO_DISABLE_IN_12_HR = 5;
+  const HOUR_TO_DISABLE_IN_24_HR = 17;
+
   it("should disable times matched by filterTime prop", () => {
     const { container: timeComponent } = render(
-      <TimeComponent filterTime={(time) => getHours(time) !== 17} />,
+      <TimeComponent
+        filterTime={(time) => getHours(time) !== HOUR_TO_DISABLE_IN_24_HR}
+      />,
+    );
+
+    const disabledTimeItems = timeComponent.querySelectorAll(
+      ".react-datepicker__time-list-item--disabled",
+    );
+
+    const disabledAllFilterTimes = Array.from(disabledTimeItems).every(
+      (disabledTimeItem) => {
+        const disabledTimeItemValue = disabledTimeItem.textContent.trim();
+        return (
+          disabledTimeItemValue.startsWith(`${HOUR_TO_DISABLE_IN_12_HR}:`) ||
+          disabledTimeItemValue.startsWith(`${HOUR_TO_DISABLE_IN_24_HR}:`)
+        );
+      },
+    );
+
+    expect(disabledAllFilterTimes).toBe(true);
+  });
+
+  it("should add aria-disabled to the disabled times matched by filterTime prop", () => {
+    const { container: timeComponent } = render(
+      <TimeComponent
+        filterTime={(time) => getHours(time) !== HOUR_TO_DISABLE_IN_24_HR}
+      />,
     );
 
     const disabledTimeItems = timeComponent.querySelectorAll(
       ".react-datepicker__time-list-item--disabled",
     );
-    expect(disabledTimeItems.length).toBe(2);
 
     const allDisabledTimeItemsHaveAriaDisabled = Array.from(
       disabledTimeItems,