Remove duplicate entries of required netcdf variables in FCI reader

[pnuu]

While testing things to speed-up FCI reader, I noticed there were some duplicate/triplicate entries in the FCI reader YAML listing the required netcdf variables. Each of these in themselves caused extra file access, so this also speeds up the reader a tiny bit.

[mraspaud]

LGTM

[codecov]

Codecov Report

Merging #2634 (f3c4c79) into main (ee63577) will increase coverage by 0.02%.
Report is 18 commits behind head on main.
The diff coverage is n/a.

@@            Coverage Diff             @@
##             main    #2634      +/-   ##
==========================================
+ Coverage   95.18%   95.20%   +0.02%     
==========================================
  Files         354      354              
  Lines       51316    51368      +52     
==========================================
+ Hits        48846    48906      +60     
+ Misses       2470     2462       -8     

Flag	Coverage Δ
behaviourtests	4.24% <ø> (-0.01%)	⬇️
unittests	95.83% <ø> (+0.02%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

see 14 files with indirect coverage changes

[pnuu]

There could be some others that are read twice even if not listed, like data/mtg_geos_projection bringing in all its attributes which are listed also separately. I'll see if this is true and clean also these.

[pnuu]

Yep, all the separately listed attributes of data/mtg_geos_projection were already read when collecting the parent.

[coveralls]

Pull Request Test Coverage Report for Build 6822460998

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 95.782%

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Totals
Change from base Build 6816647681:	0.0%
Covered Lines:	49032
Relevant Lines:	51191

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💛 - Coveralls

[ameraner]

LGTM, well spotted!