[BUG] plot_title with framestyle shows subplot of title

[jamblejoe]

Setting theframestyle attribute to anything but :none makes the title subplot appear, see e.g.

plot(plot([1,2,3]), plot([1,2,3]); border=:grid, plot_title="abc")

Backends

This bug occurs on ( insert x below )

Backend	yes	no	untested
gr (default)	x
pyplot	x
plotlyjs		x
pgfplotsx			x
unicodeplots		x
inspectdr			x
gaston			x

Versions

Plots.jl version: 1.25.7
Backend version (]st -m <backend(s)>):
Output of versioninfo():

julia> versioninfo()
Julia Version 1.7.1
Commit ac5cc99908 (2021-12-22 19:35 UTC)
Platform Info:
  OS: Linux (x86_64-pc-linux-gnu)
  CPU: Intel(R) Core(TM) i7-9700 CPU @ 3.00GHz
  WORD_SIZE: 64
  LIBM: libopenlibm
  LLVM: libLLVM-12.0.1 (ORCJIT, skylake)

[t-bltg]

Odd, we explicitly disabled framestyle for the title subplot

Plots.jl/src/pipeline.jl

Line 309 in 2a7d2d7

subplot[:framestyle] = :none