[meta] Remove IE11 Support from Olivero

Adding #3212691: Olivero: repat placeholder CSS for IE11

Added:

• #3262135: Olivero: Removal of the ie11-autorow CSS class
• #3262139: Olivero: Removal of checking for 'Esc' on keyup when checking for the Escape key
• #3262156: Olivero: Simplification of the grid layouts to use CSS grid (instead of Flexbox)

Actually, just tagging potentially required children. Some of them are should–haves.

Opened #3306098: Remove .woff font files

#3306098: Remove .woff font files landed! 👍

Updated issue summary.

Added #3321004: Remove IE11 hack from fieldset.css which also blocks #3087006: Drop .stylelintignore in 10.x

I think only #3262156: Olivero: Simplification of the grid layouts to use CSS grid (instead of Flexbox) remains here. Downgrading to major, as there is no problem if we don't complete this, it is only removing some technical debt.

Is an issue needed for this item in the Issue Summary, "Ability to use negative numbers when specifying grid columns.'?

In #16 @longwave suggests that this is complete.

I tried to confirm that pinging the Olivero maintainers in #olivero in November but haven't had a response. I tried also in #core-development in December but didn't get a response there either.

So, are we done here?

Changing status in another attempt to get feedback.

Still several references in the CSS that can likely be removed in a new child issue:

core/themes/olivero/css/components/header-search-narrow.pcss.css:    background-image: linear-gradient(var(--color--primary-50), var(--color--primary-50)); /* Two values are needed for IE11 support. */
core/themes/olivero/css/components/header-search-narrow.pcss.css:      /* IE11's high contrast show will not show the background image, so we show the text. */
core/themes/olivero/css/components/node.css:  background-image: linear-gradient(var(--color--primary-50), var(--color--primary-50)); /* Two values are needed for IE11 support. */
core/themes/olivero/css/components/search-results.pcss.css:    background-image: linear-gradient(var(--color--primary-50), var(--color--primary-50)); /* Two values are needed for IE11 support. */
core/themes/olivero/css/components/button.pcss.css:    IE11 doesn't work properly on button elements so we only do
core/themes/olivero/css/components/header-search-wide.css:  z-index: 1; /* Ensure left border shows above social region in IE11. */
core/themes/olivero/css/components/header-search-wide.css:  background-image: linear-gradient(var(--color--primary-50), var(--color--primary-50)); /* Two values are needed for IE11 support. */
core/themes/olivero/css/components/search-results.css:  background-image: linear-gradient(var(--color--primary-50), var(--color--primary-50)); /* Two values are needed for IE11 support. */
core/themes/olivero/css/components/navigation/nav-primary-no-js.pcss.css:       * because it will break IE11 and earlier versions of MS Edge.
core/themes/olivero/css/components/header-search-wide.pcss.css:  z-index: 1; /* Ensure left border shows above social region in IE11. */
core/themes/olivero/css/components/header-search-wide.pcss.css:  background-image: linear-gradient(var(--color--primary-50), var(--color--primary-50)); /* Two values are needed for IE11 support. */
core/themes/olivero/css/components/navigation/nav-primary-no-js.css:       * because it will break IE11 and earlier versions of MS Edge.
core/themes/olivero/css/components/navigation/nav-primary-wide.pcss.css:        overflow: visible; /* Necessary to view icon in IE11 */
core/themes/olivero/css/components/header-search-narrow.css:  background-image: linear-gradient(var(--color--primary-50), var(--color--primary-50)); /* Two values are needed for IE11 support. */
core/themes/olivero/css/components/header-search-narrow.css:  /* IE11's high contrast show will not show the background image, so we show the text. */
core/themes/olivero/css/components/navigation/nav-primary-wide.css:    overflow: visible; /* Necessary to view icon in IE11 */
core/themes/olivero/css/components/button.css:    IE11 doesn't work properly on button elements so we only do
core/themes/olivero/css/components/node.pcss.css:    background-image: linear-gradient(var(--color--primary-50), var(--color--primary-50)); /* Two values are needed for IE11 support. */

Opened #3519513: Remove remaining IE11 support from Olivero

#3519513: Remove remaining IE11 support from Olivero landed so I think we are done here - setting to NR for someone to check that I haven't missed anything.

Only found references in Claro as shown below and made a sibling issue for that.

$ grep -ri IE11 --exclude-dir="node_modules" --exclude-dir="assets" core
core/themes/claro/js/tableselect.js:        // is preferable, but not supported by IE11.
core/themes/claro/js/tableselect.js:          // Determine add/remove with ternary since IE11 does not support the

Therefore closing this meta.

Thanks to everyone who kept this meta up to date.