Bump Go to 1.26.3

[stuggi]

• Go: 1.24.4 -> 1.26.3
• operator-sdk: v1.41.1 -> v1.42.3
• golangci-lint: v2.7.2 -> v2.12.2
• GOTOOLCHAIN_VERSION: go1.24.0 -> go1.26.0
• go-toolset image: 1.24 -> 1.26
• .ci-operator.yaml: ci-build-root-golang-1.24-sdk-1.41.1 -> ci-build-root-golang-1.26-sdk-1.42.3
• ginkgo: v2.28.2 -> v2.32.0
• gomega: v1.42.0 -> v1.42.1
• gophercloud: v2.8.0 -> v2.13.0
• golang.org/x/exp: bumped to latest

Disabled govet inline analyzer in .golangci.yaml — Go 1.26 emits false-positive "cannot inline: type parameter inference not yet supported" for generic functions like maps.Copy and slices.Sorted.

Jira: OSPRH-30997

Depends-On: openstack-k8s-operators/openstack-operator#1977
Depends-On: openstack-k8s-operators/install_yamls#1153

[openshift-ci]

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[centosinfra-prod-github-app]

Build failed (check pipeline). Post recheck (without leading slash)
to rerun all jobs. Make sure the failure cause has been resolved before
you rerun jobs.

https://gateway-cloud-softwarefactory.apps.ocp.cloud.ci.centos.org/zuul/t/rdoproject.org/buildset/48809c67907547f58f3f068a1eb6688a

❌ openstack-meta-content-provider FAILURE in 12m 12s
⚠️ nova-operator-kuttl SKIPPED Skipped due to failed job openstack-meta-content-provider
⚠️ nova-operator-tempest-multinode SKIPPED Skipped due to failed job openstack-meta-content-provider
⚠️ nova-operator-tempest-multinode-ceph SKIPPED Skipped due to failed job openstack-meta-content-provider

[centosinfra-prod-github-app]

Build failed (check pipeline). Post recheck (without leading slash)
to rerun all jobs. Make sure the failure cause has been resolved before
you rerun jobs.

https://gateway-cloud-softwarefactory.apps.ocp.cloud.ci.centos.org/zuul/t/rdoproject.org/buildset/9075463376f64fd4bece8911585fe4a9

❌ openstack-meta-content-provider FAILURE in 15m 23s
⚠️ nova-operator-kuttl SKIPPED Skipped due to failed job openstack-meta-content-provider
⚠️ nova-operator-tempest-multinode SKIPPED Skipped due to failed job openstack-meta-content-provider
⚠️ nova-operator-tempest-multinode-ceph SKIPPED Skipped due to failed job openstack-meta-content-provider

[centosinfra-prod-github-app]

This change depends on a change that failed to merge.

Change openstack-k8s-operators/openstack-operator#1977 is needed.

[stuggi]

recheck