Chunk options `#+echo` not correctly parsed

[votti]

Symptom

Running the demo data I got errors:

Pipeline_SampleAnnotation_R:

processing file: /tmp/Rtmp4HVNRw/file1b74e41ef83803/SampleAnnotation.spin.Rmd
  |...............................                                                             |  33%                  
Quitting from lines  at lines 2-36 (/tmp/Rtmp4HVNRw/file1b74e41ef83803/SampleAnnotation.spin.Rmd)
Error:
! object 'sa' not found

MonoallelicExpression_pipeline_MAE_Results_R:

processing file: /tmp/RtmpxJMIWB/file1d4052152736d3/Results.spin.Rmd
  |.................................                                                           |  36% [unnamed-chunk-2]
Quitting from lines  at lines 160-164 [unnamed-chunk-2] (/tmp/RtmpxJMIWB/file1d4052152736d3/Results.spin.Rmd)
Error:
! object 'melt_dt' not found
Backtrace:
 1. ggplot2::ggplot(melt_dt, aes(variable, value))

Debugging

Investigating I noticed these errors were directly downstream of #+echo=F.

Manually converting the R script using knitr:spin I noticed that this accidentally gets converted into:

{recho=F}
```

## Proposed solution
Add a space between `#+` and `echo`: all `#+echo` comments with `#+ echo` 

## Environment
```
R version 4.3.3 (2024-02-29)
Platform: x86_64-conda-linux-gnu (64-bit)
Running under: Ubuntu 23.10

Matrix products: default
BLAS/LAPACK: /home/vitoz/mambaforge/envs/drop_env/lib/libopenblasp-r0.3.27.so;  LAPACK version 3.12.0

locale:
[1] LC_CTYPE=en_US.UTF-8       LC_NUMERIC=C              
[3] LC_TIME=de_CH.UTF-8        LC_COLLATE=en_US.UTF-8    
[5] LC_MONETARY=de_CH.UTF-8    LC_MESSAGES=en_US.UTF-8   
[7] LC_PAPER=de_CH.UTF-8       LC_NAME=C                 
[9] LC_ADDRESS=C               LC_TELEPHONE=C            
[11] LC_MEASUREMENT=de_CH.UTF-8 LC_IDENTIFICATION=C       

time zone: Europe/Zurich
tzcode source: system (glibc)

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base     

other attached packages:
[1] knitr_1.46        tidyr_1.3.1       magrittr_2.0.3    data.table_1.15.2

loaded via a namespace (and not attached):
[1] utf8_1.2.4       R6_2.5.1         tidyselect_1.2.0 xfun_0.43       
[5] glue_1.7.0       tibble_3.2.1     pkgconfig_2.0.3  dplyr_1.1.4     
[9] generics_0.1.3   lifecycle_1.0.4  cli_3.6.2        fansi_1.0.6     
[13] vctrs_0.6.5      compiler_4.3.3   purrr_1.0.2      tools_4.3.3     
[17] evaluate_0.23    pillar_1.9.0     yaml_2.3.8       rlang_1.1.3    
```

[vyepez88]

Many thanks! I also noticed this on Friday. I'm meeting the rest of the development meeting later today to address this today!