[CI-13182]: Use snapshot-mode instead of snapshotMode

The kaniko flag `snapshotMode` is deprecated in favor of `snapshot-mode`. The default value of `snapshot-mode` is `full`. As a result, the `optimize` flag set in Harness CI's `BuildAndPushToDocker` steps doesn't behave as expected because the `full` mode triggers a full filesystem scan which is slow. The `optimize` flag in Harness translates to `snapshot-mode=redo` which means only filesystem deltas are compared which is much faster. 

This change fixes the flag name being sent to Kaniko executor. I verified that the executor present in the current version already supports this flag as shown below:

```
hemanthkumarmantri@Hemanth Kumar harness-core % docker run -it --entrypoint /kaniko/executor plugins/kaniko:1.8.10 --help | grep snapshot-mode
      --snapshot-mode string                      Change the file attributes inspected during snapshotting (default "full")
      --snapshotMode string                       This flag is deprecated. Please use '--snapshot-mode'.
```

.drone.yml

@@ -11,7 +11,7 @@ platform:
 
 steps:
 - name: build
-  image: golang:1.22.4
+  image: golang:1.22
   commands:
   - go test ./...
   - sh scripts/build.sh
@@ -178,7 +178,7 @@ pool:
 
 steps:
 - name: build
-  image: golang:1.22.4
+  image: golang:1.22
   commands:
   - go test ./...
   - sh scripts/build.sh

docker/acr/Dockerfile.linux.amd64

@@ -1,5 +1,5 @@
-FROM gcr.io/kaniko-project/executor:v1.23.2
+FROM gcr.io/kaniko-project/executor:v1.20.1
 
-ENV KANIKO_VERSION=1.23.2
+ENV KANIKO_VERSION=1.20.1
 ADD release/linux/amd64/kaniko-acr /kaniko/
 ENTRYPOINT ["/kaniko/kaniko-acr"]

docker/acr/Dockerfile.linux.arm64

@@ -1,8 +1,8 @@
-FROM gcr.io/kaniko-project/executor:v1.23.0
+FROM gcr.io/kaniko-project/executor:v1.20.1
 
 ENV HOME /root
 ENV USER root
 
-ENV KANIKO_VERSION=1.23.0
+ENV KANIKO_VERSION=1.20.1
 ADD release/linux/arm64/kaniko-acr /kaniko/
 ENTRYPOINT ["/kaniko/kaniko-acr"]

docker/docker/Dockerfile.linux.amd64

@@ -1,5 +1,5 @@
-FROM gcr.io/kaniko-project/executor:v1.23.2
+FROM gcr.io/kaniko-project/executor:v1.20.1
 
-ENV KANIKO_VERSION=1.23.2
+ENV KANIKO_VERSION=1.20.1
 ADD release/linux/amd64/kaniko-docker /kaniko/
 ENTRYPOINT ["/kaniko/kaniko-docker"]

docker/docker/Dockerfile.linux.arm64

@@ -1,8 +1,8 @@
-FROM gcr.io/kaniko-project/executor:v1.23.2
+FROM gcr.io/kaniko-project/executor:v1.20.1
 
 ENV HOME /root
 ENV USER root
 
-ENV KANIKO_VERSION=1.23.2
+ENV KANIKO_VERSION=1.20.1
 ADD release/linux/arm64/kaniko-docker /kaniko/
 ENTRYPOINT ["/kaniko/kaniko-docker"]

docker/ecr/Dockerfile.linux.amd64

@@ -1,5 +1,5 @@
-FROM gcr.io/kaniko-project/executor:v1.23.2
+FROM gcr.io/kaniko-project/executor:v1.20.1
 
-ENV KANIKO_VERSION=1.23.2
+ENV KANIKO_VERSION=1.20.1
 ADD release/linux/amd64/kaniko-ecr /kaniko/
 ENTRYPOINT ["/kaniko/kaniko-ecr"]

docker/ecr/Dockerfile.linux.arm64

@@ -1,8 +1,8 @@
-FROM gcr.io/kaniko-project/executor:v1.23.2
+FROM gcr.io/kaniko-project/executor:v1.20.1
 
 ENV HOME /root
 ENV USER root
-ENV KANIKO_VERSION=1.23.2
+ENV KANIKO_VERSION=1.20.1
 
 ADD release/linux/arm64/kaniko-ecr /kaniko/
 ENTRYPOINT ["/kaniko/kaniko-ecr"]

docker/gar/Dockerfile.linux.amd64

@@ -1,5 +1,5 @@
-FROM gcr.io/kaniko-project/executor:v1.23.2
+FROM gcr.io/kaniko-project/executor:v1.20.1
 
-ENV KANIKO_VERSION=1.23.2
+ENV KANIKO_VERSION=1.20.1
 ADD release/linux/amd64/kaniko-gar /kaniko/
 ENTRYPOINT ["/kaniko/kaniko-gar"]

docker/gar/Dockerfile.linux.arm64

@@ -1,8 +1,8 @@
-FROM gcr.io/kaniko-project/executor:v1.23.2
+FROM gcr.io/kaniko-project/executor:v1.20.1
 
 ENV HOME /root
 ENV USER root
-ENV KANIKO_VERSION=1.23.2
+ENV KANIKO_VERSION=1.20.1
 
 ADD release/linux/arm64/kaniko-gar /kaniko/
 ENTRYPOINT ["/kaniko/kaniko-gar"]

docker/gcr/Dockerfile.linux.amd64

@@ -1,5 +1,5 @@
-FROM gcr.io/kaniko-project/executor:v1.23.2
+FROM gcr.io/kaniko-project/executor:v1.20.1
 
-ENV KANIKO_VERSION=1.23.2
+ENV KANIKO_VERSION=1.20.1
 ADD release/linux/amd64/kaniko-gcr /kaniko/
 ENTRYPOINT ["/kaniko/kaniko-gcr"]

docker/gcr/Dockerfile.linux.arm64

@@ -1,8 +1,8 @@
-FROM gcr.io/kaniko-project/executor:v1.23.2
+FROM gcr.io/kaniko-project/executor:v1.20.1
 
 ENV HOME /root
 ENV USER root
-ENV KANIKO_VERSION=1.23.2
+ENV KANIKO_VERSION=1.20.1
 
 ADD release/linux/arm64/kaniko-gcr /kaniko/
 ENTRYPOINT ["/kaniko/kaniko-gcr"]

go.mod

@@ -47,4 +47,4 @@ require (
 	gopkg.in/yaml.v3 v3.0.1 // indirect
 )
 
-go 1.22.4
+go 1.22.0