fix(syntax): minor error in minted detection regex

refer: #2142

Author: lervag

autoload/vimtex/syntax/p/minted.vim

@@ -153,7 +153,7 @@ function! s:parse_minted_constructs() abort " {{{1
     endif
 
     " Single line minted environments
-    let l:lang = matchstr(l:line, '\\begin{minted}\%(\s*\[\[^\]]*\]\)\?\s*{\zs\w\+\ze}')
+    let l:lang = matchstr(l:line, '\\begin{minted}\%(\s*\[[^\]]*\]\)\?\s*{\zs\w\+\ze}')
     if !empty(l:lang)
       call l:db.register(l:lang)
       continue

test/test-syntax/test-minted.tex

@@ -117,4 +117,10 @@
 $ ls -l
 \end{longss}
 
+\begin{minted}[breaklines]{json}
+{
+  "test": 1
+}
+\end{minted}
+
 \end{document}

test/test-syntax/test-minted.vim

@@ -16,4 +16,6 @@ call assert_true(vimtex#syntax#in('texMintedZoneShellsession', 116, 1))
 " edit
 " call assert_true(vimtex#syntax#in('pythonFunction', 38, 5))
 
+call assert_true(vimtex#syntax#in('texMintedZoneJson', 121, 1))
+
 call vimtex#test#finished()