MudInput: Fix outline label conflict with third-party CSS

[danielchalmers]

Description

Fixes an issue mentioned in #10653 (comment) where Bootstrap CSS was setting a default value for float on legend elements which caused ours to render incorrectly since #10385.

Now we apply a reset on the aforementioned property using a deeper selector which should take precedence (haven't actually tested with bootstrap).

How Has This Been Tested?

visually

Type of Changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation (fix or improvement to the website or code docs)

Before:

After:

Checklist

• The PR is submitted to the correct branch (dev).
• My code follows the code style of this project.
• I've added relevant tests.

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 91.79%. Comparing base (f7f07fe) to head (fc86a2a).
Report is 43 commits behind head on dev.

Additional details and impacted files

@@            Coverage Diff             @@
##              dev   #10672      +/-   ##
==========================================
+ Coverage   91.55%   91.79%   +0.23%     
==========================================
  Files         426      426              
  Lines       13305    13386      +81     
  Branches     2565     2576      +11     
==========================================
+ Hits        12182    12288     +106     
+ Misses        548      527      -21     
+ Partials      575      571       -4     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.