chore: update Go version to 1.26.1

[olegsu]

Summary

• Update Go toolchain version to 1.26.1 across the project
• Upgrade golangci-lint from 2.4.0 to 2.11.3 (required — 2.4.0 was built with Go 1.25 and can't lint Go 1.26.1 code)
• Disable newly introduced revive rules that flag pre-existing code patterns
• Fix 3 prealloc issues by preallocating slices with known capacity

Changes

Go version bump

File	From	To
.go-version	1.25.5	1.26.1
go.mod	1.25.5	1.26.1
scripts/update_assets_md/go.mod	1.24.0	1.26.1
docs/version.asciidoc	1.25.4	1.26.1
bin/.go-1.25.5.pkg	renamed	bin/.go-1.26.1.pkg
bin/go	.go-1.25.5.pkg	.go-1.26.1.pkg
bin/gofmt	.go-1.25.5.pkg	.go-1.26.1.pkg

golangci-lint upgrade

File	From	To
bin/.golangci-lint-2.4.0.pkg	renamed	bin/.golangci-lint-2.11.3.pkg
bin/golangci-lint	.golangci-lint-2.4.0.pkg	.golangci-lint-2.11.3.pkg
.golangci.yaml	—	Disable 6 new revive rules

Prealloc fixes

• internal/resources/fetching/fetchers/azure/assets_enricher.go
• internal/resources/providers/awslib/rds/provider.go
• internal/resources/providers/gcplib/inventory/provider.go

Test plan

• CI pipeline passes with the new Go version
• Linter passes (golangci-lint run exits 0)
• Build and unit tests succeed

[mergify]

This pull request does not have a backport label. Could you fix it @olegsu? 🙏
To fixup this pull request, you need to add the backport labels for the needed
branches, such as:

• backport-v./d./d./d is the label to automatically backport to the 8./d branch. /d is the digit
• backport-active-all is the label that automatically backports to all active branches.
• backport-active-8 is the label that automatically backports to all active minor branches for the 8 major.
• backport-active-9 is the label that automatically backports to all active minor branches for the 9 major.

[kubasobon]

🙏