LaTeX: Revamp the styling of all admonitions (#12508)

In LaTeX output, all admonitions now also have a title row with icon.

The ``xcolor`` LaTeX package is now required and the ``fontawesome5`` LaTeX package is needed for the icons.

CHANGES.rst

@@ -6,13 +6,23 @@ Dependencies
 
 * #12555: Drop Docutils 0.18.1 and Docutils 0.19 support.
   Patch by Adam Turner.
+* LaTeX: the ``xcolor`` package is now required (but is for example part of
+  Ubuntu ``texlive-latex-recommended`` which has always been required).
+* LaTeX: the ``fontawesome5`` LaTeX package is needed for the default choices
+  of icons now used in admonition titles in PDF output; but if unavailable the
+  PDF build will simply silently omit rendering such icons.  Check the
+  documentation of the ``iconpackage`` key of :ref:`'sphinxsetup'
+  <latexsphinxsetup>` for more.
 
 Incompatible changes
 --------------------
 
 Deprecated
 ----------
 
+* LaTeX: the ``sphinxlightbox`` environment is not used anymore, all types
+  of admonitions use (by default) only ``sphinxheavybox``.
+
 Features added
 --------------
 
@@ -85,6 +95,9 @@ Features added
   Patch by Ashley Whetter.
 * #6792: Prohibit module import cycles in :mod:`sphinx.ext.autosummary`.
   Patch by Trevor Bekolay.
+* #12508: LaTeX: Revamped styling of all admonitions, with addition of a
+  title row with icon.
+  Patch by Jean-François B.
 
 Bugs fixed
 ----------

bindep.txt

@@ -14,10 +14,13 @@ texlive-ctablestack [platform:rpm]
 texlive-gnu-freefont [platform:rpm]
 texlive-tex-gyre [platform:rpm]
 texlive-pict2e [platform:rpm]
+texlive-fontawesome5 [platform:rpm]
+texlive-xcolor [platform:rpm]
 latexmk [platform:rpm]
 
 texlive-latex-recommended [platform:dpkg]
 texlive-fonts-recommended [platform:dpkg]
+texlive-fonts-extra [platform:dpkg]
 tex-gyre [platform:dpkg]
 texlive-latex-extra [platform:dpkg]
 texlive-luatex [platform:dpkg]