Migrate `gap` helpers to tailwind (#30034)

Commands ran:

```sh
perl -p -i -e 's#gt-gap-0#tw-gap-0#g'   web_src/js/**/* templates/**/*
perl -p -i -e 's#gt-gap-1#tw-gap-0.5#g' web_src/js/**/* templates/**/*
perl -p -i -e 's#gt-gap-2#tw-gap-1#g'   web_src/js/**/* templates/**/*
perl -p -i -e 's#gt-gap-3#tw-gap-2#g'   web_src/js/**/* templates/**/*
perl -p -i -e 's#gt-gap-4#tw-gap-4#g'   web_src/js/**/* templates/**/*
perl -p -i -e 's#gt-gap-5#tw-gap-8#g'   web_src/js/**/* templates/**/*

perl -p -i -e 's#gt-gap-x-0#tw-gap-x-0#g'   web_src/js/**/* templates/**/*
perl -p -i -e 's#gt-gap-x-1#tw-gap-x-0.5#g' web_src/js/**/* templates/**/*
perl -p -i -e 's#gt-gap-x-2#tw-gap-x-1#g'   web_src/js/**/* templates/**/*
perl -p -i -e 's#gt-gap-x-3#tw-gap-x-2#g'   web_src/js/**/* templates/**/*
perl -p -i -e 's#gt-gap-x-4#tw-gap-x-4#g'   web_src/js/**/* templates/**/*
perl -p -i -e 's#gt-gap-x-5#tw-gap-x-8#g'   web_src/js/**/* templates/**/*

perl -p -i -e 's#gt-gap-y-0#tw-gap-y-0#g'   web_src/js/**/* templates/**/*
perl -p -i -e 's#gt-gap-y-1#tw-gap-y-0.5#g' web_src/js/**/* templates/**/*
perl -p -i -e 's#gt-gap-y-2#tw-gap-y-1#g'   web_src/js/**/* templates/**/*
perl -p -i -e 's#gt-gap-y-3#tw-gap-y-2#g'   web_src/js/**/* templates/**/*
perl -p -i -e 's#gt-gap-y-4#tw-gap-y-4#g'   web_src/js/**/* templates/**/*
perl -p -i -e 's#gt-gap-y-5#tw-gap-y-8#g'   web_src/js/**/* templates/**/*

2 files changed, 5 insertions, 5 deletions

diff --git a/templates/repo/diff/box.tmpl b/templates/repo/diff/box.tmpl
index 51c0aae007..9fd8593c53 100644
--- a/templates/repo/diff/box.tmpl
+++ b/templates/repo/diff/box.tmpl
@@ -1,7 +1,7 @@
 {{$showFileTree := (and (not .DiffNotAvailable) (gt .Diff.NumFiles 1))}}
 <div>
 	<div class="diff-detail-box diff-box">
-		<div class="tw-flex tw-items-center tw-flex-wrap gt-gap-3 gt-ml-1">
+		<div class="tw-flex tw-items-center tw-flex-wrap tw-gap-2 gt-ml-1">
 			{{if $showFileTree}}
 				<button class="diff-toggle-file-tree-button not-mobile btn interact-fg" data-show-text="{{ctx.Locale.Tr "repo.diff.show_file_tree"}}" data-hide-text="{{ctx.Locale.Tr "repo.diff.hide_file_tree"}}">
 					{{/* the icon meaning is reversed here, "octicon-sidebar-collapse" means show the file tree */}}
@@ -111,7 +111,7 @@
 					{{$isReviewFile := and $.IsSigned $.PageIsPullFiles (not $.IsArchived) $.IsShowingAllCommits}}
 					<div class="diff-file-box diff-box file-content {{TabSizeClass $.Editorconfig $file.Name}} gt-mt-0" id="diff-{{$file.NameHash}}" data-old-filename="{{$file.OldName}}" data-new-filename="{{$file.Name}}" {{if or ($file.ShouldBeHidden) (not $isExpandable)}}data-folded="true"{{end}}>
 						<h4 class="diff-file-header sticky-2nd-row ui top attached header tw-font-normal tw-flex tw-items-center tw-justify-between tw-flex-wrap">
-							<div class="diff-file-name tw-flex tw-items-center gt-gap-2 tw-flex-wrap">
+							<div class="diff-file-name tw-flex tw-items-center tw-gap-1 tw-flex-wrap">
 								<button class="fold-file btn interact-bg gt-p-2{{if not $isExpandable}} tw-invisible{{end}}">
 									{{if $file.ShouldBeHidden}}
 										{{svg "octicon-chevron-right" 18}}
@@ -144,7 +144,7 @@
 									<span class="gt-ml-4 gt-mono">{{ctx.Locale.Tr ($file.ModeTranslationKey $file.Mode)}}</span>
 								{{end}}
 							</div>
-							<div class="diff-file-header-actions tw-flex tw-items-center gt-gap-2 tw-flex-wrap">
+							<div class="diff-file-header-actions tw-flex tw-items-center tw-gap-1 tw-flex-wrap">
 								{{if $showFileViewToggle}}
 									<div class="ui compact icon buttons">
 										<button class="ui tiny basic button file-view-toggle" data-toggle-selector="#diff-source-{{$file.NameHash}}" data-tooltip-content="{{ctx.Locale.Tr "repo.file_view_source"}}">{{svg "octicon-code"}}</button>
diff --git a/templates/repo/diff/conversation.tmpl b/templates/repo/diff/conversation.tmpl
index 85bfe4923a..e689deb1bf 100644
--- a/templates/repo/diff/conversation.tmpl
+++ b/templates/repo/diff/conversation.tmpl
@@ -9,7 +9,7 @@
 	<div class="conversation-holder" data-path="{{$comment.TreePath}}" data-side="{{if lt $comment.Line 0}}left{{else}}right{{end}}" data-idx="{{$comment.UnsignedLine}}">
 		{{if $resolved}}
 			<div class="ui attached header resolved-placeholder tw-flex tw-items-center tw-justify-between">
-				<div class="ui grey text tw-flex tw-items-center tw-flex-wrap gt-gap-2">
+				<div class="ui grey text tw-flex tw-items-center tw-flex-wrap tw-gap-1">
 					{{svg "octicon-check" 16 "icon gt-mr-2"}}
 					<b>{{$resolveDoer.Name}}</b> {{ctx.Locale.Tr "repo.issues.review.resolved_by"}}
 					{{if $invalid}}
@@ -22,7 +22,7 @@
 						</a>
 					{{end}}
 				</div>
-				<div class="tw-flex tw-items-center gt-gap-3">
+				<div class="tw-flex tw-items-center tw-gap-2">
 					<button id="show-outdated-{{$comment.ID}}" data-comment="{{$comment.ID}}" class="ui tiny labeled button show-outdated tw-flex tw-items-center">
 						{{svg "octicon-unfold" 16 "gt-mr-3"}}
 						{{ctx.Locale.Tr "repo.issues.review.show_resolved"}}