chore(prompts): add skill and prompt to update supported Go versions (#1561)

* chore(prompts): add supported Go version update skill and prompt

* docs: add usage for supported Go version update prompt

.github/skills/gosec-update-go-versions/SKILL.md

@@ -0,0 +1,78 @@
+---
+name: Update Supported Go Versions
+description: Update gosec to the latest patch versions of the two latest supported Go major versions using go.dev release data.
+---
+
+# Update supported Go versions across the repository
+
+Use this skill when you want to bump repository Go versions to the newest patch releases of the latest two supported Go major versions.
+
+Reference source for versions:
+- https://go.dev/doc/devel/release
+
+## Required behavior
+
+1. Fetch and parse the release page.
+2. Detect the latest two Go major.minor series and their latest patch versions.
+   - Example shape: latest series `1.26.x` and previous series `1.25.x`.
+3. Derive:
+   - `latest_patch` (for newest series, full patch string, e.g. `1.26.3`)
+   - `previous_patch` (for second newest series, full patch string, e.g. `1.25.9`)
+   - `latest_minor` (e.g. `1.26`)
+   - `previous_minor` (e.g. `1.25`)
+4. Apply updates carefully across all relevant files.
+
+## Version update rules
+
+Use repository-wide search and update all applicable occurrences, including but not limited to:
+
+- GitHub Actions workflow `go-version` values:
+  - Matrix entries for supported versions must include exactly the two patch versions:
+    - `previous_patch`
+    - `latest_patch`
+  - Single-version setup-go steps should use `latest_patch`.
+- Build argument and build tool defaults:
+  - `GO_VERSION=<major.minor>` style values should use `latest_minor`.
+- Module/toolchain minimum version markers:
+  - `go.mod` `go` directive should be set to `previous_minor.0`.
+  - Embedded temporary `go.mod` contents in tests/benchmarks should use `previous_minor` (without patch) unless file style requires otherwise.
+- Documentation and skill/prompt metadata that state supported versions:
+  - Update text to match the new supported pair (`previous_minor` and `latest_minor`).
+  - Update "requires Go X or newer" style statements to `previous_minor`.
+
+## Discovery checklist (must run)
+
+Search the full repository for version markers and review each hit:
+
+- `go-version:`
+- `setup-go`
+- `GO_VERSION`
+- `golang:`
+- `^go [0-9]+\.[0-9]+(\.[0-9]+)?$`
+- `Go 1.`
+- `1\.[0-9]+\.[0-9]+`
+
+Do not change unrelated historical references unless they represent active supported-version policy.
+
+## Validation
+
+1. Confirm all intended files were updated and no obvious supported-version location was missed.
+2. Run targeted checks:
+   - `go test ./...`
+3. Re-run search to ensure old supported pair is removed from active config/docs.
+
+## Git and PR workflow
+
+1. Create branch: `chore/update-go-versions-<latest_minor>`
+2. Commit message: `chore(go): update supported Go versions to <previous_patch> and <latest_patch>`
+3. Push branch.
+4. Open PR to `master` with:
+   - Title: `chore(go): update supported Go versions to <previous_patch> and <latest_patch>`
+   - Body summary listing key files changed and source link to go.dev release page.
+
+## Output requirements
+
+- Report detected versions (`previous_patch`, `latest_patch`, `previous_minor`, `latest_minor`).
+- List all updated files grouped by category (workflows, build config, module/tests, docs/metadata).
+- Report test command result.
+- Report branch name, commit SHA, PR title, and PR URL.