CI: Make grabpl and lint-drone standalone steps (#41644)

* Extract grabpl download as separate step

* Change image to alpine

* Change image to curlimage

* Change image to alpine-curl

* Extract lint-drone step

* Add lint-drone to release and main pipelines

* Rename lint_drone to lint_drone_step

* Sign drone

scripts/drone/pipelines/main.star

@@ -1,5 +1,6 @@
 load(
     'scripts/drone/steps/lib.star',
+    'lint_drone_step',
     'lint_backend_step',
     'lint_frontend_step',
     'codespell_step',
@@ -53,6 +54,7 @@ def get_steps(edition, is_downstream=False):
     publish = edition != 'enterprise' or is_downstream
     include_enterprise2 = edition == 'enterprise'
     steps = [
+        lint_drone_step(),
         enterprise_downstream_step(edition=edition),
         codespell_step(),
         shellcheck_step(),

scripts/drone/pipelines/pr.star

@@ -1,5 +1,6 @@
 load(
     'scripts/drone/steps/lib.star',
+    'lint_drone_step',
     'lint_backend_step',
     'lint_frontend_step',
     'codespell_step',
@@ -46,6 +47,7 @@ def pr_pipelines(edition):
     variants = ['linux-x64', 'linux-x64-musl', 'osx64', 'win64', 'armv6',]
     include_enterprise2 = edition == 'enterprise'
     steps = [
+        lint_drone_step(),
         codespell_step(),
         shellcheck_step(),
         lint_backend_step(edition=edition),

scripts/drone/pipelines/release.star

@@ -1,5 +1,6 @@
 load(
     'scripts/drone/steps/lib.star',
+    'lint_drone_step',
     'test_release_ver',
     'build_image',
     'publish_image',
@@ -82,6 +83,7 @@ def get_steps(edition, ver_mode):
         tries = 5
 
     steps = [
+        lint_drone_step(),
         codespell_step(),
         shellcheck_step(),
         lint_backend_step(edition=edition),