Regression with inherit from pkg::a-b between 8.1.0 and 8.0.0

[llrs-roche]

On some packages I help maintain there are some (internal) documentation pages with a suffix -class.
When we want to inherit from them with the following line:

#' @inheritSection teal.code::`qenv-class` Code

Which results on an error to find the alias even if it is present:

✖ In topic 'teal_data-class': @inherits failed to find topic teal.code::`qenv-class`.

The only way around it was to downgrade to roxygen 8.0.0 and document the package again.
However, this creates a problem on the CI that documents the package again and has removed the code block.

Other information

Linking ( [teal.code::qenv-class] ) works fine.
Attemps made that didn't solve the issue:

• teal.code::qenv-class
• teal.code::qenv-class
• "teal.code::qenv-class"
• teal.code::"qenv-class"

[averissimo]

I believe this is due to the usage of rdtools::topic_split in get_rd (before #1904 rlang::parse_expr was being used)

rdtools::topic_split("teal.code::`qenv-class`")
#> $package
#> [1] "teal.code"
#> 
#> $topic
#> [1] "`qenv-class`"

as.character(rlang::parse_expr("teal.code::`qenv-class`")[[3]])
#> [1] "qenv-class"

roxygen2:::get_rd_from_help("teal.code", "`qenv-class`", source = "a")
#> ✖ In topic 'a': @inherits failed to find topic teal.code::`qenv-class`.
#> NULL
roxygen2:::get_rd_from_help("teal.code", "qenv-class", source = "a")
#> \title{Reproducible class with environment and code}\name{qenv-class}\alias{qenv-class}\keyword{internal}\description{
#> Reproducible class with environment and code.
#> }\section{Slots}{
#> 
#> \describe{
#> \item{\code{.xData}}{(\code{environment}) environment with content was generated by the evaluation}
#> 
#> \item{\code{code}}{(\verb{named list} of \code{character}) representing code necessary to reproduce the environment.
#> Read more in Code section.
#> of the \code{code} slot.}
#> }}\section{Code}{
#> 
#> 
#> Each code element is a character representing one call. Each element is named with the random
#> identifier to make sure uniqueness when joining. Each element has possible attributes:
#> \itemize{
#> \item \code{warnings} (\code{character}) the warnings output when evaluating the code element.
#> \item \code{messages} (\code{character}) the messages output when evaluating the code element.
#> \item \code{dependency} (\code{character}) names of objects that appear in this call and gets affected by this call,
#> separated by \verb{<-} (objects on LHS of \verb{<-} are affected by this line, and objects on RHS are affecting this line).
#> }
#> }