Bump cssom from 0.3.4 to 0.3.8 (#13461)

Bumps [cssom](https://github.com/NV/CSSOM) from 0.3.4 to 0.3.8.
- [Release notes](https://github.com/NV/CSSOM/releases)
- [Commits](https://github.com/NV/CSSOM/commits)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

Co-authored-by: dependabot-preview[bot] <27856297+dependabot-preview[bot]@users.noreply.github.com>

yarn.lock

@@ -3369,9 +3369,9 @@ csso@^3.5.0:
     css-tree "1.0.0-alpha.29"
 
 cssom@0.3.x, "cssom@>= 0.3.2 < 0.4.0":
-  version "0.3.4"
-  resolved "https://registry.yarnpkg.com/cssom/-/cssom-0.3.4.tgz#8cd52e8a3acfd68d3aed38ee0a640177d2f9d797"
-  integrity sha512-+7prCSORpXNeR4/fUP3rL+TzqtiFfhMvTd7uEqMdgPvLPt4+uzFUeufx5RHjGTACCargg/DiEt/moMQmvnfkog==
+  version "0.3.8"
+  resolved "https://registry.yarnpkg.com/cssom/-/cssom-0.3.8.tgz#9f1276f5b2b463f2114d3f2c75250af8c1a36f4a"
+  integrity sha512-b0tGHbfegbhPJpxpiBPU2sCkigAqtM9O121le6bbOlgyV+NyGyCmVfJ6QW9eRjz8CpNfWEOYBIMIGRYkLwsIYg==
 
 cssstyle@^1.0.0:
   version "1.1.1"