[28.x backport] remove some remnants from CLI "experimental" config option

[thaJeztah]

• backport remove some remnants from CLI "experimental" config option #6235

---

Experimental is always enabled (977d3ae), and the Experimental field in plugin metadata was deprecated in 977d3ae and removed in commit 6a50c4f.

The second commit reformats a test-table for readability.

- A picture of a cute animal (not mandatory but encouraged)

[codecov-commenter]

Codecov Report

❌ Patch coverage is 0% with 1 line in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
e2e/internal/fixtures/fixtures.go	0.00%	1 Missing ⚠️

📢 Thoughts on this report? Let us know!

[thaJeztah]

That's an interesting one; Build-cache perhaps?

#21 [engine 2/4] RUN apk --no-cache upgrade openssh-client &&   apk --no-cache add shadow openssh-server &&   groupadd -f docker &&   useradd --create-home --shell /bin/sh --password $(head -c32 /dev/urandom | base64) penguin &&   usermod -aG docker penguin &&   ssh-keygen -A
#21 0.117 fetch https://dl-cdn.alpinelinux.org/alpine/v3.22/main/x86_64/APKINDEX.tar.gz
#21 0.188 fetch https://dl-cdn.alpinelinux.org/alpine/v3.22/community/x86_64/APKINDEX.tar.gz
#21 0.474 (1/3) Upgrading openssh-keygen (10.0_p1-r7 -> 10.0_p1-r8)
#21 0.482 (2/3) Upgrading openssh-client-common (10.0_p1-r7 -> 10.0_p1-r8)
#21 0.500 (3/3) Upgrading openssh-client-default (10.0_p1-r7 -> 10.0_p1-r8)
#21 0.510 Executing busybox-1.37.0-r18.trigger
#21 0.517 OK: 41 MiB in 75 packages
#21 0.602 fetch https://dl-cdn.alpinelinux.org/alpine/v3.22/main/x86_64/APKINDEX.tar.gz
#21 0.668 fetch https://dl-cdn.alpinelinux.org/alpine/v3.22/community/x86_64/APKINDEX.tar.gz
#21 0.980 (1/3) Installing openssh-server-common (10.0_p1-r8)
#21 0.983 (2/3) Installing openssh-server (10.0_p1-r8)
#21 1.000 (3/3) Installing shadow (4.17.3-r0)
#21 1.014 Executing busybox-1.37.0-r18.trigger
#21 1.018 OK: 44 MiB in 78 packages
#21 1.112 OpenSSL version mismatch. Built against 3050003f, you have 30500020
#21 ERROR: process "/bin/sh -c apk --no-cache upgrade openssh-client &&   apk --no-cache add shadow openssh-server &&   groupadd -f docker &&   useradd --create-home --shell /bin/sh --password $(head -c32 /dev/urandom | base64) penguin &&   usermod -aG docker penguin &&   ssh-keygen -A" did not complete successfully: exit code: 255
------
 > [engine 2/4] RUN apk --no-cache upgrade openssh-client &&   apk --no-cache add shadow openssh-server &&   groupadd -f docker &&   useradd --create-home --shell /bin/sh --password $(head -c32 /dev/urandom | base64) penguin &&   usermod -aG docker penguin &&   ssh-keygen -A:
0.510 Executing busybox-1.37.0-r18.trigger
0.517 OK: 41 MiB in 75 packages
0.602 fetch https://dl-cdn.alpinelinux.org/alpine/v3.22/main/x86_64/APKINDEX.tar.gz
0.668 fetch https://dl-cdn.alpinelinux.org/alpine/v3.22/community/x86_64/APKINDEX.tar.gz
0.980 (1/3) Installing openssh-server-common (10.0_p1-r8)
0.983 (2/3) Installing openssh-server (10.0_p1-r8)
1.000 (3/3) Installing shadow (4.17.3-r0)
1.014 Executing busybox-1.37.0-r18.trigger
1.018 OK: 44 MiB in 78 packages
1.112 OpenSSL version mismatch. Built against 3050003f, you have 30500020

[thaJeztah]

failure is unrelated