Update dependency cssnano to v4.1.1

[dev-mend-for-github-com]

This PR contains the following updates:

Package	Type	Update	Change
cssnano	dependencies	patch	4.1.0 -> 4.1.1

By merging this PR, the issue #24 will be automatically resolved and closed:

Severity	CVSS Score	Vulnerability	Reachability
High	8.1	WS-2019-0063
High	7.5	WS-2019-0032
High	7.5	WS-2021-0152
High	7.3	CVE-2020-8116
Medium	5.3	CVE-2021-23364
Medium	5.3	CVE-2021-23382
Medium	5.3	CVE-2021-29060

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Release Notes

cssnano/cssnano (cssnano)

v4.1.1

Compare Source

4.1.1 - 2018-09-25

Bug Fixes

• css-declaration-sorter was removed from default prevent.
• postcss-normalize-timing-functions doesn't lowercased property anymore.
• postcss-normalize-positons now handles uppercase properties.
• postcss-normalize-url now is case-insensitive.
• postcss-merge-idents now is case-insensitive.
• postcss-merge-rules now is case-insensitive.
• postcss-minify-selectors now is case-insensitive.
• postcss-minify-font-values now is case-insensitive.
• postcss-normalize-unicode now has correct dependencies.
• postcss-minify-params now has correct dependencies.

Other changes

• cssnano-preset-advanced use Autoprefixer 9.
• use PostCSS 7 in all plugins.

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