title: check_rhub is trying and failing to install BiocManager
body: <p>I am trying to submit an R package to CRAN. I am at the stage of testing it with check_rhub(). If I use a platform like linux-x86_64-centos-epel or windows-x86_64-release it installs without any problems. However, when I try one of the debian platforms, such as debian-clang-devel, it tries to install BiocManager manager and then fails with the error</p>
  <pre><code>Error: Bioconductor version '3.13' requires R version '4.1'; R version is too new; see
    https://bioconductor.org/install
  Execution halted
  </code></pre>
  <p>This is odd because my package does not need bioconductor and I do not have BiocManager on any of the dependency list. In fact, there is a single dependency, reticulate, and my DESCRIPTION looks like this</p>
  <pre><code>Imports:
    reticulate
  </code></pre>
  <p>The full error trace from check_rhub() is</p>
  <pre><code>
  ❯ Build failed during preparation or aborted
  
  [...]
  Type 'demo()' for some demos, 'help()' for on-line help, or
  'help.start()' for an HTML browser interface to help.
  Type 'q()' to quit R.
  
  &gt; install.packages('BiocManager')
  Installing package into '/home/docker/R'
  (as 'lib' is unspecified)
  trying URL 'https://cloud.r-project.org/src/contrib/BiocManager_1.30.12.tar.gz'
  Content type 'application/x-gzip' length 261321 bytes (255 KB)
  ==================================================
  downloaded 255 KB
  
  * installing *source* package 'BiocManager' ...
  ** package 'BiocManager' successfully unpacked and MD5 sums checked
  ** using staged installation
  ** R
  ** inst
  ** byte-compile and prepare package for lazy loading
  ** help
  *** installing help indices
  ** building package indices
  ** installing vignettes
  ** testing if installed package can be loaded from temporary location
  ** testing if installed package can be loaded from final location
  ** testing if installed package keeps a record of temporary installation path
  * DONE (BiocManager)
  
  The downloaded source packages are in
      '/tmp/RtmpOzRXET/downloaded_packages'
  &gt; 
  &gt; 
  
  ─ Querying package dependencies
  
    % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                   Dload  Upload   Total   Spent    Left  Speed
  100  162k  100  162k    0     0   802k      0 --:--:-- --:--:-- --:--:--  802k
  
  R Under development (unstable) (2021-04-25 r80223) -- &quot;Unsuffered Consequences&quot;
  Copyright (C) 2021 The R Foundation for Statistical Computing
  Platform: x86_64-pc-linux-gnu (64-bit)
  
  R is free software and comes with ABSOLUTELY NO WARRANTY.
  You are welcome to redistribute it under certain conditions.
  Type 'license()' or 'licence()' for distribution details.
  
    Natural language support but running in an English locale
  
  R is a collaborative project with many contributors.
  Type 'contributors()' for more information and
  'citation()' on how to cite R or R packages in publications.
  
  Type 'demo()' for some demos, 'help()' for on-line help, or
  'help.start()' for an HTML browser interface to help.
  Type 'q()' to quit R.
  
  Error: Bioconductor version '3.13' requires R version '4.1'; R version is too new; see
    https://bioconductor.org/install
  Execution halted
  
  ─ Installing package dependencies
  
  /opt/R-devel/bin:/usr/local/bin:/usr/bin:/bin:/usr/local/games:/usr/games
  clang
  Debian clang version 11.0.1-2
  Target: x86_64-pc-linux-gnu
  Thread model: posix
  InstalledDir: /usr/bin
  clang++ -std=gnu++14
  Debian clang version 11.0.1-2
  Target: x86_64-pc-linux-gnu
  Thread model: posix
  InstalledDir: /usr/bin
  Pandoc:
  /usr/bin/pandoc
  -rwxr-xr-x 1 root root 63606952 Apr 26 06:04 /usr/bin/pandoc
  -rwxr-xr-x 1 root root 58111640 Apr 26 06:04 /usr/bin/pandoc-citeproc
  
  R Under development (unstable) (2021-04-25 r80223) -- &quot;Unsuffered Consequences&quot;
  Copyright (C) 2021 The R Foundation for Statistical Computing
  Platform: x86_64-pc-linux-gnu (64-bit)
  
  R is free software and comes with ABSOLUTELY NO WARRANTY.
  You are welcome to redistribute it under certain conditions.
  Type 'license()' or 'licence()' for distribution details.
  
    Natural language support but running in an English locale
  
  R is a collaborative project with many contributors.
  Type 'contributors()' for more information and
  'citation()' on how to cite R or R packages in publications.
  
  Type 'demo()' for some demos, 'help()' for on-line help, or
  'help.start()' for an HTML browser interface to help.
  Type 'q()' to quit R.
  
  Error: Bioconductor version '3.13' requires R version '4.1'; R version is too new; see
    https://bioconductor.org/install
  Execution halted
  Error: Bioconductor version '3.13' requires R version '4.1'; R version is too new; see
    https://bioconductor.org/install
  Execution halted
  Build step 'Execute shell' marked build as failure
  
  </code></pre>