Specify building in Release with CMake in docs

[jatkinson1000]

Specify building in Release with CMake in docs

Fixes #1094

Task List

• Linked an issue above that captures the requirements of this PR
• [-] Defined the tests that specify a complete and functioning change
• [-] Implemented the source code change that satisfies the tests
• [-] Commented all code so that it can be understood without additional context
• [-] No new warnings are generated or they are mentioned below
• The documentation has been updated (or an issue has been created to do so)
• Relevant labels (e.g., enhancement, bug) have been applied to this PR
• This change conforms to the conventions described in the README

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Change Description

As discussed in #1094 installation docs do not specify adding a CMake Build Type flag for Release.
This can lead to new users naively building in debug which is orders of magnitude slower.
This PR adds the flag explicitly.

In addition I note that decomp is documented with CMake modern, whilst neXtSIM is CMake classic.
I took the opportunity to standardise these in 54284b5
If we would prefer to standardise all to Modern I can do that here.

Further I believe there is a small issue with decomp in that Release was not specified at configure time via CMake_BUILD_TYPE.
It was applied at build time via --config but I believe this is only for multi-config generators like VSCode andf Ninja, so would not have been applied for Makefiles.
I am assuming users of this code are using a Makefile approach, but this should be confirmed by more experienced developers.

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Test Description

No code changes, therefore no tests changes.

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Documentation Impact

Installation docs are the target of the updates described above.

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Other Details

None

[Mikolaj-A-Kowalski]

Just one comment, but I think it is good to go.

[jatkinson1000]

I also checked the Dockerfiles for CI and applied similar changes there in 681046d

[Mikolaj-A-Kowalski]

Are we sure of the URL for the XOIS?
It seems that this is not the first failure in the Docker build; see the logs.

It seems that the Jul 1 scheduled job also failed with similar issue?

[jatkinson1000]

The address seems correct, but the branch might not be, see: Downloading_and_compiling_the_XIOS_library

I tried amending in cca91bf but it seems to still fail.

Update: cannot ping , so I think server is down, can retry later.

[TomMelt]

Perhaps we can discuss tomorrow. Overall happy with simplification and addition to docs. But I dont fully understand the dockerfile changes

[TomMelt]

quick question... why did you change back to xios2? I think @joewallwork moved us to XIOS3.

Is this a mistake?

[TomMelt]

Also the install directory has been changed from /xios to effectively ./XIOS

[jatkinson1000]

That was a change to follow the XIOS docs (linked above) after @Mikolaj-A-Kowalski queried whether we are using the correct url and command.

My intention was to drop if it didn't fix the issue which I can do now, given we seem to have established it's just the server being intermittent.

[jatkinson1000]

Just rebased and dropped cca91bf