ref(issue-details): Remove useHasStreamlinedUI hook and legacy UI code (#112465)

Remove the `useHasStreamlinedUI` hook which always returned `true`,
along with
all legacy (non-streamlined) UI code paths gated behind it.

Changes:
- Delete `useHasStreamlinedUI` from `utils.tsx`
- Remove all call sites and simplify conditional branches in
  `groupEventDetailsContent`, `groupEventDetails`, and `groupDetails`
- Remove dead imports, styled components, and functions that were only
  reachable from the legacy path (`renderGroupStatusBanner`,
  `trackTabChanged`, `StyledLayoutBody`, `StyledLayoutMain`,
  `GroupStatusBannerWrapper`, `GroupTabPanels`, `NotFoundMessage`,
  `StyledDataSection`, etc.)
- Remove `jest.mock` overrides of the hook in test files
- Simplify `inputWithStorage.tsx` to no longer gate on the hook

Agent transcript:
https://claudescope.sentry.dev/share/N42GnuAIP46Yfs6hbcGKQ4Uybjtnlxsgws23v5IjV_o

Author: chromy

static/app/components/activity/note/inputWithStorage.tsx

@@ -7,7 +7,6 @@ import type {MentionChangeEvent} from 'sentry/components/activity/note/types';
 import type {NoteType} from 'sentry/types/alerts';
 import {localStorageWrapper} from 'sentry/utils/localStorage';
 import {StreamlinedNoteInput} from 'sentry/views/issueDetails/streamline/sidebar/note';
-import {useHasStreamlinedUI} from 'sentry/views/issueDetails/utils';
 
 type InputProps = React.ComponentProps<typeof NoteInput>;
 
@@ -61,7 +60,6 @@ function NoteInputWithStorage({
   source,
   ...props
 }: Props) {
-  const hasStreamlinedUi = useHasStreamlinedUI();
   const value = useMemo(() => {
     if (text) {
       return text;
@@ -137,7 +135,7 @@ function NoteInputWithStorage({
   );
 
   // Make sure `this.props` does not override `onChange` and `onCreate`
-  if (hasStreamlinedUi && source === 'issue-details') {
+  if (source === 'issue-details') {
     return (
       <StreamlinedNoteInput
         text={value}

static/app/components/archivedBox.spec.tsx

@@ -1,6 +1,5 @@
 import {DateTime} from 'sentry/components/dateTime';
 import {Duration} from 'sentry/components/duration';
-import {BannerContainer, BannerSummary} from 'sentry/components/events/styles';
 import {t} from 'sentry/locale';
 import type {Group, IgnoredStatusDetails} from 'sentry/types/group';
 import {GroupSubstatus} from 'sentry/types/group';
@@ -58,13 +57,3 @@ export function renderArchiveReason({substatus, statusDetails}: ArchivedBoxProps
 
   return t('This issue has been archived forever.');
 }
-
-export function ArchivedBox({substatus, statusDetails}: ArchivedBoxProps) {
-  return (
-    <BannerContainer priority="default">
-      <BannerSummary>
-        <span>{renderArchiveReason({substatus, statusDetails})}</span>
-      </BannerSummary>
-    </BannerContainer>
-  );
-}