Squashed commit of the following:

commit 95479c8ad744db48386a5c78e54ef8da80e9120b
Author: Chris Lane <chris@chris-allen-lane.com>
Date:   Wed Apr 28 12:26:32 2021 -0400

    chore(version): bump version to 4.2.1

commit 6956f51cae
Author: Chris Lane <chris@chris-allen-lane.com>
Date:   Wed Apr 28 12:24:21 2021 -0400

    fix(Makefile): `vendor-update`

    Update the `vendor-update` build target to run `go mod vendor` after
    updating dependencies.

commit 0aca411279
Author: Chris Lane <chris@chris-allen-lane.com>
Date:   Wed Apr 28 12:23:24 2021 -0400

    chore(deps): update dependencies

commit e847956b02
Author: Chris Lane <chris@chris-allen-lane.com>
Date:   Wed Apr 28 08:26:51 2021 -0400

    chore(deps): build updates

    - Upgrade `go` to `1.16.3`

    - Attempt to fix build errors regarding dependencies

vendor/github.com/alecthomas/chroma/lexers/i/idris.go

@@ -6,14 +6,18 @@ import (
 )
 
 // Idris lexer.
-var Idris = internal.Register(MustNewLexer(
+var Idris = internal.Register(MustNewLazyLexer(
 	&Config{
 		Name:      "Idris",
 		Aliases:   []string{"idris", "idr"},
 		Filenames: []string{"*.idr"},
 		MimeTypes: []string{"text/x-idris"},
 	},
-	Rules{
+	idrisRules,
+))
+
+func idrisRules() Rules {
+	return Rules{
 		"root": {
 			{`^(\s*)(%lib|link|flag|include|hide|freeze|access|default|logging|dynamic|name|error_handlers|language)`, ByGroups(Text, KeywordReserved), nil},
 			{`(\s*)(--(?![!#$%&*+./<=>?@^|_~:\\]).*?)$`, ByGroups(Text, CommentSingle), nil},
@@ -76,5 +80,5 @@ var Idris = internal.Register(MustNewLexer(
 			{`\d+`, LiteralStringEscape, Pop(1)},
 			{`\s+\\`, LiteralStringEscape, Pop(1)},
 		},
-	},
-))
+	}
+}

vendor/github.com/alecthomas/chroma/lexers/i/igor.go

@@ -6,7 +6,7 @@ import (
 )
 
 // Igor lexer.
-var Igor = internal.Register(MustNewLexer(
+var Igor = internal.Register(MustNewLazyLexer(
 	&Config{
 		Name:            "Igor",
 		Aliases:         []string{"igor", "igorpro"},
@@ -14,7 +14,11 @@ var Igor = internal.Register(MustNewLexer(
 		MimeTypes:       []string{"text/ipf"},
 		CaseInsensitive: true,
 	},
-	Rules{
+	igorRules,
+))
+
+func igorRules() Rules {
+	return Rules{
 		"root": {
 			{`//.*$`, CommentSingle, nil},
 			{`"([^"\\]|\\.)*"`, LiteralString, nil},
@@ -28,5 +32,5 @@ var Igor = internal.Register(MustNewLexer(
 			{`.`, Text, nil},
 			{`\n|\r`, Text, nil},
 		},
-	},
-))
+	}
+}

vendor/github.com/alecthomas/chroma/lexers/i/ini.go

@@ -6,14 +6,18 @@ import (
 )
 
 // Ini lexer.
-var Ini = internal.Register(MustNewLexer(
+var Ini = internal.Register(MustNewLazyLexer(
 	&Config{
 		Name:      "INI",
 		Aliases:   []string{"ini", "cfg", "dosini"},
 		Filenames: []string{"*.ini", "*.cfg", "*.inf", ".gitconfig", ".editorconfig"},
 		MimeTypes: []string{"text/x-ini", "text/inf"},
 	},
-	Rules{
+	iniRules,
+))
+
+func iniRules() Rules {
+	return Rules{
 		"root": {
 			{`\s+`, Text, nil},
 			{`[;#].*`, CommentSingle, nil},
@@ -21,5 +25,5 @@ var Ini = internal.Register(MustNewLexer(
 			{`(.*?)([ \t]*)(=)([ \t]*)(.*(?:\n[ \t].+)*)`, ByGroups(NameAttribute, Text, Operator, Text, LiteralString), nil},
 			{`(.+?)$`, NameAttribute, nil},
 		},
-	},
-))
+	}
+}

vendor/github.com/alecthomas/chroma/lexers/i/io.go

@@ -6,14 +6,18 @@ import (
 )
 
 // Io lexer.
-var Io = internal.Register(MustNewLexer(
+var Io = internal.Register(MustNewLazyLexer(
 	&Config{
 		Name:      "Io",
 		Aliases:   []string{"io"},
 		Filenames: []string{"*.io"},
 		MimeTypes: []string{"text/x-iosrc"},
 	},
-	Rules{
+	ioRules,
+))
+
+func ioRules() Rules {
+	return Rules{
 		"root": {
 			{`\n`, Text, nil},
 			{`\s+`, Text, nil},
@@ -36,5 +40,5 @@ var Io = internal.Register(MustNewLexer(
 			{`\+/`, CommentMultiline, Pop(1)},
 			{`[+/]`, CommentMultiline, nil},
 		},
-	},
-))
+	}
+}