do not exclude unit-openapi.yaml from releases

[andypost]

Proposed changes

The file is expluded from release tarbal so to build unitctl this file should be fetched additionally to sources

Checklist

Before creating a PR, run through this checklist and mark each as complete:

• I have read the contributing guidelines.
• I have signed the F5 Contributor License Agreement (CLA).
• If applicable, I have added tests that prove my fix is effective or that my feature works.
• If applicable, I have checked that any relevant tests pass after adding my changes.
• I have updated any relevant documentation (README.md and/or CHANGELOG.md).

[ac000]

• rebased with master

$ git range-diff d26ead09...18d8e542
-:  -------- > 1:  630848a3 Remove SUPPORT.md
-:  -------- > 2:  ad736f9f php: Add a new to 8.5 SAPI callback, pre_request_init
1:  d26ead09 ! 3:  18d8e542 do not exclude unit-openapi.yaml from releases
    @@ Metadata
      ## Commit message ##
         do not exclude unit-openapi.yaml from releases
     
    +    Signed-off-by: Andrew Clayton <ac@sigsegv.uk>
    +
      ## .gitattributes ##
     @@
      pkg/**    export-ignore