Correct ruff failures (#8732)

* fix: Correct ruff problems

* updating DIRECTORY.md

* fix: Fix pre-commit errors

* updating DIRECTORY.md

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Co-authored-by: github-actions <${GITHUB_ACTOR}@users.noreply.github.com>

conversions/prefix_conversions_string.py

@@ -96,7 +96,7 @@ def add_si_prefix(value: float) -> str:
     for name_prefix, value_prefix in prefixes.items():
         numerical_part = value / (10**value_prefix)
         if numerical_part > 1:
-            return f"{str(numerical_part)} {name_prefix}"
+            return f"{numerical_part!s} {name_prefix}"
     return str(value)
 
 
@@ -111,7 +111,7 @@ def add_binary_prefix(value: float) -> str:
     for prefix in BinaryUnit:
         numerical_part = value / (2**prefix.value)
         if numerical_part > 1:
-            return f"{str(numerical_part)} {prefix.name}"
+            return f"{numerical_part!s} {prefix.name}"
     return str(value)