[repo] Update stale.yml - reduce days before stale to 900

[TimothyMothra]

Follow up to https://github.com/open-telemetry/opentelemetry-dotnet/issues/5776

This PR moves the days-before-issue-stale from 1000 to 900. The ultimate goal is to get this down to 300 days.

Counts of issues

• Currently 320 open issues (Sept 9, 2024).
• older than 300 days (Nov 14, 2023) = 147 issues
• older than 600 days (Jan 18, 2023) = 65 issues
• older than 900 days (Mar 24 2022) = 14 issues

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 86.22%. Comparing base (6250307) to head (565c304). Report is 307 commits behind head on main.

Additional details and impacted files

[](https://app.codecov.io/gh/open-telemetry/opentelemetry-dotnet/pull/5822?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=open-telemetry) ```diff @@ Coverage Diff @@ ## main #5822 +/- ## ========================================== + Coverage 83.38% 86.22% +2.83% ========================================== Files 297 257 -40 Lines 12531 11150 -1381 ========================================== - Hits 10449 9614 -835 + Misses 2082 1536 -546 ``` | [Flag](https://app.codecov.io/gh/open-telemetry/opentelemetry-dotnet/pull/5822/flags?src=pr&el=flags&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=open-telemetry) | Coverage Δ | | |---|---|---| | [unittests](https://app.codecov.io/gh/open-telemetry/opentelemetry-dotnet/pull/5822/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=open-telemetry) | `?` | | | [unittests-Project-Experimental](https://app.codecov.io/gh/open-telemetry/opentelemetry-dotnet/pull/5822/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=open-telemetry) | `85.88% <ø> (?)` | | | [unittests-Project-Stable](https://app.codecov.io/gh/open-telemetry/opentelemetry-dotnet/pull/5822/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=open-telemetry) | `86.19% <ø> (?)` | | | [unittests-Solution](https://app.codecov.io/gh/open-telemetry/opentelemetry-dotnet/pull/5822/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=open-telemetry) | `85.96% <ø> (?)` | | | [unittests-UnstableCoreLibraries-Experimental](https://app.codecov.io/gh/open-telemetry/opentelemetry-dotnet/pull/5822/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=open-telemetry) | `85.76% <ø> (?)` | | Flags with carried forward coverage won't be shown. [Click here](https://docs.codecov.io/docs/carryforward-flags?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=open-telemetry#carryforward-flags-in-the-pull-request-comment) to find out more. [see 213 files with indirect coverage changes](https://app.codecov.io/gh/open-telemetry/opentelemetry-dotnet/pull/5822/indirect-changes?src=pr&el=tree-more&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=open-telemetry)

[Kielek]

@CodeBlanch, @TimothyMothra what is the target value?

[TimothyMothra]

@CodeBlanch, @TimothyMothra what is the target value?

@Kielek, the target value is 300. I've been moving in slow steps to collect feedback and review issues before they're closed.