perf(misc): use arrays instead of slices where possible

Arrays have a fixed size in go, while slices don't, making the former way
faster than the latter: https://go-benchmarks.com/array-vs-slice

internal/reader/icon/finder.go

@@ -251,7 +251,7 @@ func findIconURLsFromHTMLDocument(body io.Reader, contentType string) ([]string,
 		return nil, fmt.Errorf("icon: unable to read document: %v", err)
 	}
 
-	queries := []string{
+	queries := [...]string{
 		"link[rel='icon' i][href]",
 		"link[rel='shortcut icon' i][href]",
 		"link[rel='icon shortcut' i][href]",

internal/reader/processor/reading_time.go

@@ -65,7 +65,7 @@ func updateEntryReadingTime(store *storage.Storage, feed *model.Feed, entry *mod
 	}
 
 	// Define watch time fetching scenarios
-	watchTimeScenarios := []struct {
+	watchTimeScenarios := [...]struct {
 		shouldFetch func(*model.Entry) bool
 		fetchFunc   func(string) (int, error)
 		platform    string

internal/reader/rewrite/content_rewrite_functions.go

@@ -107,7 +107,7 @@ func addDynamicImage(entryContent string) string {
 	doc := goquery.NewDocumentFromNode(parserHtml)
 
 	// Ordered most preferred to least preferred.
-	candidateAttrs := []string{
+	candidateAttrs := [...]string{
 		"data-src",
 		"data-original",
 		"data-orig",
@@ -124,7 +124,7 @@ func addDynamicImage(entryContent string) string {
 		"data-380src",
 	}
 
-	candidateSrcsetAttrs := []string{
+	candidateSrcsetAttrs := [...]string{
 		"data-srcset",
 	}