PR: Fix extra line in range when formatting selection

[remisalmon]

Description of Changes

• Wrote at least one-line docstrings (for any new functions)
• Added unit test(s) covering the changes (if testable)

• Included a screenshot or animation (if affecting the UI, see Licecap)

This fixes an issue where formatting a line selected by a double click includes and formats the next line.

In some cases this even breaks the code; when using black and selecting a line outside the range of the text the formatting wraps around:

> cat -n temp.py
     1	a = 'hello'
     2	b = ["a", "very", "very", "very", "very", "very", "very", "very", "very", "long", "line"]
     3	c =  42

> black --diff --line-ranges 3-3 temp.py
--- temp.py	2023-12-27 04:53:07.369501+00:00
+++ temp.py	2023-12-27 04:58:40.860306+00:00
@@ -1,3 +1,3 @@
 a = 'hello'
 b = ["a", "very", "very", "very", "very", "very", "very", "very", "very", "long", "line"]
-c =  42
+c = 42
would reformat temp.py

> black --diff --line-ranges 3-4 temp.py
--- temp.py	2023-12-27 04:53:07.369501+00:00
+++ temp.py	2023-12-27 04:58:57.782151+00:00
@@ -1,3 +1,15 @@
-a = 'hello'
-b = ["a", "very", "very", "very", "very", "very", "very", "very", "very", "long", "line"]
-c =  42
+a = "hello"
+b = [
+    "a",
+    "very",
+    "very",
+    "very",
+    "very",
+    "very",
+    "very",
+    "very",
+    "very",
+    "long",
+    "line",
+]
+c = 42
would reformat temp.py 

Note sure if a bug or a feature, https://black.readthedocs.io/en/stable/usage_and_configuration/the_basics.html#line-ranges says that

Black may still format lines outside of the ranges for multi-line statements.

This issue (minus the wraparound thing) also exists and is fixed with autopep8.

Before:

Screen.Recording.2023-12-26.at.9.51.44.PM.mp4

After:

Screen.Recording.2023-12-26.at.9.52.45.PM.mp4

Issue(s) Resolved

None, let me know if I need to create one?

Affirmation

By submitting this Pull Request or typing my (user)name below,
I affirm the Developer Certificate of Origin
with respect to all commits and content included in this PR,
and understand I am releasing the same under Spyder's MIT (Expat) license.

I certify the above statement is true and correct: remisalmon

[ccordoba12]

Looks good to me, thanks @remisalmon!