refactor: remove use of tmos "github.com/tendermint/tendermint/libs/os"

[facundomedica]

Description

Given that there were just a handful of usages and these were replaced with just one or two lines of code, no new package was necessary.

Closes: #13112

---

Author Checklist

All items are required. Please add a note to the item if the item is not applicable and
please add links to any relevant follow up issues.

I have...

• included the correct type prefix in the PR title
• added ! to the type prefix if API or client breaking change
• targeted the correct branch (see PR Targeting)
• provided a link to the relevant issue or specification
• followed the guidelines for building modules
• included the necessary unit and integration tests
• added a changelog entry to CHANGELOG.md
• included comments for documenting Go code
• updated the relevant documentation or specification
• reviewed "Files changed" and left comments if necessary
• confirmed all CI checks have passed

Reviewers Checklist

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your handle next to the items reviewed if you only reviewed selected items.

I have...

• confirmed the correct type prefix in the PR title
• confirmed ! in the type prefix if API or client breaking change
• confirmed all author checklist items have been addressed
• reviewed state machine logic
• reviewed API design and naming
• reviewed documentation is accurate
• reviewed tests and test coverage
• manually tested (if applicable)

[codecov]

Codecov Report

Merging #13113 (090d3a2) into main (bf8f015) will increase coverage by 0.05%.
The diff coverage is 14.28%.

❗ Current head 090d3a2 differs from pull request most recent head 319bc3b. Consider uploading reports for the commit 319bc3b to get more accurate results

@@            Coverage Diff             @@
##             main   #13113      +/-   ##
==========================================
+ Coverage   53.19%   53.24%   +0.05%     
==========================================
  Files         643      647       +4     
  Lines       55032    55116      +84     
==========================================
+ Hits        29274    29348      +74     
- Misses      23424    23432       +8     
- Partials     2334     2336       +2     

Impacted Files	Coverage Δ
simapp/app.go	77.30% <0.00%> (-0.48%)	⬇️
x/genutil/client/cli/gentx.go	0.00% <0.00%> (ø)
x/genutil/types/genesis_state.go	51.42% <0.00%> (ø)
x/genutil/utils.go	53.70% <0.00%> (ø)
x/upgrade/keeper/keeper.go	83.14% <0.00%> (-0.07%)	⬇️
x/genutil/client/cli/init.go	67.85% <66.66%> (+0.58%)	⬆️
core/appconfig/config.go
tx/textual/valuerenderer/timestamp.go	100.00% <0.00%> (ø)
tx/textual/valuerenderer/dec.go	72.41% <0.00%> (ø)
tx/textual/valuerenderer/bytes.go	53.84% <0.00%> (ø)
... and 3 more

[tac0turtle]

utACK