dockerfile: don't use +x for chmod

[Bixilon]

docker does not understand it, 555 is sufficient here too.

[mzihlmann]

how comes this didnt pop up in integration tests 😕

[mzihlmann]

from last release

/workspace # ls -la /kaniko
total 97448
drwxr-xr-x    1 0        0             4096 Jan 10 00:03 .
drwxr-xr-x    1 0        0             4096 Jan 12 14:33 ..
drwxr-xr-x    2 0        0             4096 Jan  6 22:54 .docker
-rwxr-xr-x    1 0        0         11484877 Jan  9 21:22 docker-credential-acr-env
-rwxr-xr-x    1 0        0         13049993 Jan  9 21:21 docker-credential-ecr-login
-rwxr-xr-x    1 0        0         11043147 Jan  9 21:21 docker-credential-gcr
-rwxr-xr-x    1 0        0         50327736 Jan 10 00:03 executor
drwxr-xr-x    3 0        0             4096 Nov  6 21:17 ssl
-rwx--x--x    1 0        0           870496 Dec  7  2021 tini
-rwxr-xr-x    1 0        0         12972216 Jan 10 00:03 warmer

[Bixilon]

See moby/buildkit#1951 and moby/buildkit#5380, apparently it depends on the buildkit version and it is supported as of 0.17 (2024), my local docker version is 27.5.1+dfsg4, so I am lacking 2 versions behind and that seems to make the difference (debian)

[mzihlmann]

yes also just saw it, documentation is confusingly also not yet updated.
I don't care about that syntax here, so let's make it compatible.

[Bixilon]

And the docker documentation is outdated, and moby/buildkit#6430 does not seem to be deployed yet.