[flake8-simplify] - Fix syntax error in autofix (SIM114) (#9704)

## Summary

A fix for
#8402 (comment)

Improves the code, as well. :)

## Test Plan

`cargo test`

crates/ruff_linter/resources/test/fixtures/flake8_simplify/SIM114.py

@@ -143,3 +143,8 @@ def func():
 
 if a: b  # here's a comment
 elif c: b
+
+
+if(x > 200): pass
+elif(100 < x and x < 200 and 300 < y and y < 800):
+	pass

crates/ruff_linter/src/rules/flake8_simplify/rules/if_with_same_arms.rs

@@ -126,19 +126,9 @@ fn merge_branches(
         return Err(anyhow::anyhow!("Expected colon after test"));
     };
 
-    let mut following_branch_tokenizer =
-        SimpleTokenizer::starts_at(following_branch.test.end(), locator.contents());
-
-    // Identify the colon (`:`) at the end of the following branch's test.
-    let Some(following_branch_colon) =
-        following_branch_tokenizer.find(|token| token.kind == SimpleTokenKind::Colon)
-    else {
-        return Err(anyhow::anyhow!("Expected colon after test"));
-    };
-
     let main_edit = Edit::deletion(
-        locator.full_line_end(current_branch_colon.end()),
-        locator.full_line_end(following_branch_colon.end()),
+        locator.full_line_end(current_branch.end()),
+        locator.full_line_end(following_branch.end()),
     );
 
     // If the test isn't parenthesized, consider parenthesizing it.

crates/ruff_linter/src/rules/flake8_simplify/snapshots/ruff_linter__rules__flake8_simplify__tests__SIM114_SIM114.py.snap

@@ -247,4 +247,13 @@ SIM114.py:144:1: SIM114 Combine `if` branches using logical `or` operator
     |
     = help: Combine `if` branches
 
+SIM114.py:148:1: SIM114 Combine `if` branches using logical `or` operator
+    |
+148 | / if(x > 200): pass
+149 | | elif(100 < x and x < 200 and 300 < y and y < 800):
+150 | |     pass
+    | |________^ SIM114
+    |
+    = help: Combine `if` branches
+
 

crates/ruff_linter/src/rules/flake8_simplify/snapshots/ruff_linter__rules__flake8_simplify__tests__preview__SIM114_SIM114.py.snap

@@ -442,5 +442,26 @@ SIM114.py:144:1: SIM114 [*] Combine `if` branches using logical `or` operator
 144     |-if a: b  # here's a comment
 145     |-elif c: b
     144 |+if a or c: b  # here's a comment
+146 145 | 
+147 146 | 
+148 147 | if(x > 200): pass
+
+SIM114.py:148:1: SIM114 [*] Combine `if` branches using logical `or` operator
+    |
+148 | / if(x > 200): pass
+149 | | elif(100 < x and x < 200 and 300 < y and y < 800):
+150 | |     pass
+    | |________^ SIM114
+    |
+    = help: Combine `if` branches
+
+ℹ Safe fix
+145 145 | elif c: b
+146 146 | 
+147 147 | 
+148     |-if(x > 200): pass
+149     |-elif(100 < x and x < 200 and 300 < y and y < 800):
+150     |-	pass
+    148 |+if(x > 200) or (100 < x and x < 200 and 300 < y and y < 800): pass