refactor: Remove redundant github.Ptr calls

[alexandear]

This PR adds redundantptr linter to detect github.Ptr(x) calls that can be replaced with simple &x.

[codecov]

Codecov Report

❌ Patch coverage is 94.73684% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 93.70%. Comparing base (5124fac) to head (28ea325).
⚠️ Report is 6 commits behind head on master.

Files with missing lines	Patch %	Lines
example/commitpr/main.go	0.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #4145      +/-   ##
==========================================
- Coverage   93.74%   93.70%   -0.04%     
==========================================
  Files         211      210       -1     
  Lines       19685    18996     -689     
==========================================
- Hits        18453    17801     -652     
+ Misses       1034     1009      -25     
+ Partials      198      186      -12     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[gmlewis]

Thank you, @alexandear!
Just one file deletion, then LGTM.
Awaiting second LGTM+Approval from any other contributor to this repo before merging.

cc: @stevehipwell - @zyfy29 - @Not-Dhananjay-Mishra - @munlicode

[gmlewis]

I think this file can be completely deleted.

[alexandear]

We can't remove this file because it's used in tests:

❯ go test ./...
--- FAIL: TestRun (0.16s)
    analysistest.go:417: src/has-warnings/main.go:9:2: cannot find package "github.com/google/go-github/v84/github" in any of:
                /opt/homebrew/Cellar/go/1.26.2/libexec/src/github.com/google/go-github/v84/github (from $GOROOT)
                /Users/alexandear/src/github.com/google/go-github/tools/redundantptr/testdata/src/github.com/google/go-github/v84/github (from $GOPATH)
    analysistest.go:417: /Users/alexandear/src/github.com/google/go-github/tools/redundantptr/testdata/src/has-warnings/main.go:9:2: could not import github.com/google/go-github/v84/github (invalid package name: "")
    analysistest.go:417: /Users/alexandear/src/github.com/google/go-github/tools/redundantptr/testdata/src/no-warnings/main.go:8:8: could not import github.com/google/go-github/v84/github (invalid package name: "")
    analysistest.go:431: error analyzing redundantptr@has-warnings: analysis skipped due to errors in package
    analysistest.go:431: error analyzing redundantptr@no-warnings: analysis skipped due to errors in package
FAIL
FAIL    tools/redundantptr      0.379s
FAIL

The analysistest framework needs the imported packages to be available in the testdata directory structure.