Multiline strings in calls and sets don't work

[joshuataylor]

Description

{{ 'hello
world' }}

Should output:

hello
world

And

{% set foo = 'hello
world' %}
{{ foo }}

Should output:

hello
world

[What happened]

called `Result::unwrap()` on an `Err` value: Error { kind: SyntaxError, detail: Some("unexpected end of string"), name: Some("set.txt"), lineno: 22, source: None }

---------------------------- Template Source -----------------------------
  19 | {% if true %}{% set foo = "was true" %}{% endif %}
  20 | {{ foo }}
  21 | 
  22 > {{"hello
  23 | world"}}
--------------------------------------------------------------------------

thread 'test_vm' panicked at 'called `Result::unwrap()` on an `Err` value: Error { kind: SyntaxError, detail: Some("unexpected end of string"), name: Some("set.txt"), lineno: 22, source: None }

---------------------------- Template Source -----------------------------
  19 | {% if true %}{% set foo = "was true" %}{% endif %}
  20 | {{ foo }}
  21 | 
  22 > {{"hello
  23 | world"}}
--------------------------------------------------------------------------
', minijinja/tests/test_templates.rs:37:58
stack backtrace:

Additional helpful information:

• Version of minijinja: git (6cd21be656fe95db3b62250ad51315822f89686a)
• Version of rustc: rustc 1.65.0-nightly (9243168fa 2022-08-31)
• Operating system and version: Arch 5.19

What did you expect

It would not error :)

I believe this is due to https://github.com/mitsuhiko/minijinja/blob/main/minijinja/src/lexer.rs#L127 , I'm unsure if it'll break anything by removing it?