lua: Update keyword operator highlighting (#26091)

Resolves #26032 

This PR changes the highlighting for `and`, `not` and `or` in Lua from
`operator` to `keyword.operator`. [VS Code also highlights these as
keyword
operators](1483add845/Syntaxes/Lua.plist (L277-L279))
and Zed does this for other languages as well, like
[Python](813e207514/crates/languages/src/python/highlights.scm (L221-L229))
or
[Zig](813e207514/extensions/zig/languages/zig/highlights.scm (L145-L149)).

Additionally, in 813e207514 I removed
duplicate matches for existing keywords to improve readability and align
them to how keywords are generally matched across languages (see
[Rust](813e207514/crates/languages/src/rust/highlights.scm (L79-L119))
and
[Typescript](813e207514/crates/languages/src/typescript/highlights.scm (L210-L269))
for example).
Whilst contributing to the majority of the diff, this does not change
any existing highlights.

| Before | After | 
| --- | --- |
| <img width="309" alt="old"
src="https://github.com/user-attachments/assets/7790817e-4a0d-442b-b176-9a84bcc6f3c4"
/> | <img width="309" alt="PR"
src="https://github.com/user-attachments/assets/34a57962-938a-4465-9406-288f5c456aa3"
/> |


Release Notes:

- N/A

---------

Co-authored-by: Peter Tripp <peter@zed.dev>

extensions/lua/languages/lua/highlights.scm

@@ -1,74 +1,23 @@
 ;; Keywords
 
-"return" @keyword
-
-[
- "goto"
- "in"
- "local"
-] @keyword
-
-(break_statement) @keyword
-
-(do_statement
 [
   "do"
-  "end"
-] @keyword)
-
-(while_statement
-[
-  "while"
-  "do"
-  "end"
-] @keyword)
-
-(repeat_statement
-[
-  "repeat"
-  "until"
-] @keyword)
-
-(if_statement
-[
-  "if"
-  "elseif"
   "else"
-  "then"
-  "end"
-] @keyword)
-
-(elseif_statement
-[
   "elseif"
-  "then"
   "end"
-] @keyword)
-
-(else_statement
-[
-  "else"
-  "end"
-] @keyword)
-
-(for_statement
-[
   "for"
-  "do"
-  "end"
-] @keyword)
-
-(function_declaration
-[
   "function"
-  "end"
-] @keyword)
-
-(function_definition
-[
-  "function"
-  "end"
-] @keyword)
+  "goto"
+  "if"
+  "in"
+  "local"
+  "repeat"
+  "return"
+  "then"
+  "until"
+  "while"
+  (break_statement)
+] @keyword
 
 ;; Operators
 
@@ -76,7 +25,7 @@
  "and"
  "not"
  "or"
-] @operator
+] @keyword.operator
 
 [
   "+"