Use libertinus package directly

main.tex

@@ -1,5 +1,4 @@
 % Template
-\pdfminorversion=7 % Fix include image warnings
 \documentclass[twoside, a4paper, 11pt]{book}
 \usepackage[inner=35mm, outer=20mm, top=30mm, bottom=25mm]{geometry}
 
@@ -10,7 +9,7 @@
 \usepackage[T1]{fontenc} % Use T1 font encoding
 \usepackage[english]{babel} % Typographical rules
 \usepackage[varqu, varl]{inconsolata} % Better monospace font (with alternative "quote" [varqu] and "l" [varl])
-\usepackage[libertinus, type1]{newtx} % Use Libertinus font for text and math
+\usepackage{libertinus} % Libertinus font for text and math
 \usepackage{microtype} % Micro-typography improvements (slightly more compact, better to read)
 
 % Bibliography
@@ -58,10 +57,6 @@
 \usepackage[inline]{enumitem} % Customise lists
 \setitemize{noitemsep} % No space between items in itemize
 
-% Math
-\usepackage{mathtools} % More math symbols
-\usepackage{textcomp} % For special symbols
-
 % References
 \usepackage{bookmark} % Manage bookmarks
 \usepackage{etoc} % Local table of contents