feat: bump Go to 1.15.8

See siderolabs/tools#126, siderolabs/pkgs#241,
siderolabs/extras#10

Signed-off-by: Andrey Smirnov <smirnov.andrey@gmail.com>

Makefile

@@ -8,9 +8,9 @@ REGISTRY_AND_USERNAME := $(REGISTRY)/$(USERNAME)
 DOCKER_LOGIN_ENABLED ?= true
 
 ARTIFACTS := _out
-TOOLS ?= ghcr.io/talos-systems/tools:v0.3.0-19-ge54841a
-PKGS ?= v0.3.0-71-g0368166
-EXTRAS ?= v0.1.0-8-g3cb9fc9
+TOOLS ?= ghcr.io/talos-systems/tools:v0.3.0-21-g0026740
+PKGS ?= v0.3.0-72-ga0bb6ab
+EXTRAS ?= v0.1.0-9-g302cc61
 GO_VERSION ?= 1.15
 GOFUMPT_VERSION ?= abc0db2c416aca0f60ea33c23c76665f6e7ba0b6
 IMPORTVET ?= autonomy/importvet:f6b07d9