System Information
Operating system: Darwin-20.2.0-x86_64-i386-64bit 64 Bits
Graphics card: AMD Radeon Pro 570 OpenGL Engine ATI Technologies Inc. 4.1 ATI-4.2.13

Blender Version
Broken: version: 2.92.0 Beta, branch: master, commit date: 2021-02-01 15:40, hash: rBd5d8655ca15c
Worked: -

Short description of error
UI: Labels with icons create additional padding after label text (in contrast to labels without icons)

Exact steps for others to reproduce the error
Based on the following layout:

# Text only:
row = layout.row(align=True)
row.alignment = 'RIGHT'
row.label(text='Hello World')

# Text with icon:
row = layout.row(align=True)
row.alignment = 'RIGHT'
row.label(text='Hello World', icon='WORLD')

# Text only again:
row = layout.row(align=True)
row.alignment = 'RIGHT'
row.label(text='Hello World')

# Icon only:
row = layout.row(align=True)
row.alignment = 'RIGHT'
row.label(icon='WORLD')

Above code drawn in a Panel looks like this in Blender 2.83.12, 2.91.2, 2.92 and 2.93:

In the newer releases, text-only labels are right-aligned with icon-only labels.

But in the case of text and icon set in a label, there still is additional padding.