Settings UI: Fix spelling error and make spell checker happy (#41403)

## Summary of the Pull Request

- Renames `NavigatablePage` to `NavigablePage` to fix a spelling error.
- Reverts related entries in `exclude.txt` that triggered a forbidden
pattern error in the spell checker.
- The spell checker does not allow PascalCase words like
`NavigatablePage` in `exclude.txt` because of its automatic casing
rules.

 
Regression: #41285

---------

Co-authored-by: vanzue <vanzue@outlook.com>

.github/actions/spell-check/expect.txt

@@ -1025,8 +1025,6 @@ MYICON
 NAMECHANGE
 namespaceanddescendants
 nao
-Navigatable
-NavigatablePage
 NCACTIVATE
 ncc
 NCCALCSIZE

.github/actions/spell-check/patterns.txt

@@ -260,3 +260,7 @@ Process Process
 # ZoomIt menu items with accelerator keys
 E&xit
 St&yle
+
+# This matches a relative clause where the relative pronoun "that" is omitted.
+# Example: "Gets or sets the window the TitleBar should configure."
+\bthe\s+\w+\s+the\b