[PLAY-877] RTE Custom Extenion Dropdown Button Bug Fix (#3528)

[PLAY-877](https://runway.powerhrg.com/backlog_items/PLAY-877)

**What does this PR do?**
The "..." button on the top toolbar of the RTE should toggle its popover
dropdown. When clicked again while the dropdown is open, it should
close. The same behavior applies to the paragraph formatting dropdown.
Although the paragraph formatting dropdown was not mentioned in the
provided bug story, the fix involved replicating the functionality of
the "..." button in a different file.

**Screenshots:**

![image](https://github.com/user-attachments/assets/c41dcc25-ae02-4823-87b0-9c16fe311266)

![image](https://github.com/user-attachments/assets/deee8615-90a7-46f2-bf9d-05e874ef1118)

**How to test?** Steps to confirm the desired behavior:
1. Go to Playbook Components -> Format Input -> Rich Text Editor
2. Click the "..." extensions button in the RTE toolbar once to verify
that the dropdown opens, and click it again to confirm that it closes.
Repeat the same process for the paragraph formatting button also located
in the RTE toolbar.

#### Checklist:
- [x] **LABELS** Add a label: `enhancement`, `bug`, `improvement`, `new
kit`, `deprecated`, or `breaking`. See [Changelog &
Labels](https://github.com/powerhome/playbook/wiki/Changelog-&-Labels)
for details.
- [x] **DEPLOY** I have added the `milano` label to show I'm ready for a
review.
- [ ] **TESTS** I have added test coverage to my code.

playbook/app/pb_kits/playbook/pb_rich_text_editor/TipTap/MoreExtensionsDropdown.tsx

@@ -10,7 +10,7 @@ const MoreExtensionsDropdown = ({extensions}: any) => {
   const [showPopover, setShowPopover] = useState(false)
 
   const handleTogglePopover = () => {
-    setShowPopover(true)
+    setShowPopover(!showPopover)
   }
 
   const handlePopoverClose = (shouldClosePopover: boolean) => {

playbook/app/pb_kits/playbook/pb_rich_text_editor/TipTap/ToolbarDropdown.tsx

@@ -67,7 +67,7 @@ const toolbarDropdownItems = [
 
 
   const handleTogglePopover = () => {
-    setShowPopover(true)
+    setShowPopover(!showPopover)
   }
 
   const handlePopoverClose = (shouldClosePopover: boolean) => {