chore: bump Go to 1.26.4 and update GitHub Actions dependencies

[rambohe-ch]

Bump the Go toolchain to 1.26.4 to pick up Go stdlib security fixes (resolves stdlib CVEs reported in ICM 816788806):

• go.mod: go directive 1.24.13 -> 1.26.4
• Dockerfile: builder golang:1.24 -> golang:1.26.4
• CI workflows: GO_VERSION 1.24.13 -> 1.26.4

Merge open dependabot GitHub Actions bumps (PRs #296-#300):

• docker/login-action -> 3.7.0
• step-security/harden-runner -> v2.15.0
• github/codeql-action -> c793b71
• goreleaser/goreleaser-action -> v7
• crate-ci/typos -> v1.44.0

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 71.25%. Comparing base (e7a66e1) to head (d0141dd).

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #303   +/-   ##
=======================================
  Coverage   71.25%   71.25%           
=======================================
  Files           4        4           
  Lines         407      407           
=======================================
  Hits          290      290           
  Misses         98       98           
  Partials       19       19           

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[rambohe-ch]

I've run E2E tests locally, and all tests have passed.

------- END CONTROLLER LOGS -------
  < Exit [AfterEach] TOP-LEVEL - /Users/rambohe/go/src/github.com/azure/gpu-provisioner/test/e2e/suites/suite_test.go:43 @ 06/17/26 13:25:49.809 (827ms)
  > Enter [DeferCleanup (Each)] GPU NodeClaim - /Users/rambohe/go/src/github.com/azure/gpu-provisioner/test/e2e/suites/suite_test.go:584 @ 06/17/26 13:25:49.809
  STEP: waiting for created node claims to be == to 0 - /Users/rambohe/go/src/github.com/azure/gpu-provisioner/test/e2e/pkg/environment/common/expectation.go:325 @ 06/17/26 13:25:50.237
  STEP: waiting for nodes to be == to 0 - /Users/rambohe/go/src/github.com/azure/gpu-provisioner/test/e2e/suites/suite_test.go:587 @ 06/17/26 13:27:01.87
  < Exit [DeferCleanup (Each)] GPU NodeClaim - /Users/rambohe/go/src/github.com/azure/gpu-provisioner/test/e2e/suites/suite_test.go:584 @ 06/17/26 13:27:02.457 (1m12.65s)
• [329.987 seconds]
------------------------------

Ran 8 of 8 Specs in 2201.306 seconds
SUCCESS! -- 8 Passed | 0 Failed | 0 Pending | 0 Skipped
--- PASS: TestGPUNodeClaim (2201.31s)
PASS
ok  	command-line-arguments	2202.262s
make e2etests  24.74s user 12.37s system 1% cpu 37:48.42 total