callr update from CRAN

[gaborcsardi]

    ══ Failed tests ════════════════════════════════════════════════════════════════
    ── Failure ('test-utils.R:8:5'): is_complete_expression ────────────────────────
    is_complete_expression("1 1") is not TRUE
    
    `actual`:   FALSE
    `expected`: TRUE 
    Backtrace:
        ▆
     1. └─callr (local) do_tests() at test-utils.R:15:3
     2.   └─testthat::expect_true(is_complete_expression("1 1")) at test-utils.R:8:5
    ── Failure ('test-utils.R:8:5'): is_complete_expression ────────────────────────
    is_complete_expression("1 1") is not TRUE
    
    `actual`:   FALSE
    `expected`: TRUE 
    Backtrace:
        ▆
     1. ├─withr::with_envvar(c(LANGUAGE = "de_DE"), do_tests()) at test-utils.R:18:5
     2. │ └─base::force(code)
     3. └─callr (local) do_tests()
     4.   └─testthat::expect_true(is_complete_expression("1 1")) at test-utils.R:8:5