chore: manage tool versions via mise

[olerass]

We currently pin Node in two files (.nvmrc and .node-version) that can drift, Maestro sits separately in .tool-versions, and Ruby needs a manual rbenv/rvm setup of its own. Following on from #7511, the natural cleanup is to give mise full responsibility for tool versions.

This change makes mise install the single setup step:

• Maestro moves into mise.toml
• .nvmrc is removed in favor of keeping only .node-version (see below why we can't use mise.toml just yet for Node)
• Node and Ruby are wired in through mise's idiomatic version file support. They stay pinned in .node-version/.ruby-version since the CI actions actions/setup-node and ruby/setup-ruby don't support Mise yet
• For Bitrise the community nvm@1 step, which silently falls back to installing the latest Node once .nvmrc is gone, is replaced with a script step that installs mise and Node from the same .node-version pin and exposes them to all subsequent steps.

Once actions/setup-node#1421 ships we can fold the Node pin into mise.toml and drop .node-version for a single canonical pin file.

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[i1skn]

LGTM! Small question, do we want then to remove this logic

rainbow/ios/.xcode.env

Lines 34 to 46 in baf3acb

	# 2) nvm -- source it and honor .nvmrc when present. Probe absolute Homebrew
	# paths too, since `brew` itself may not be on Xcode's stripped PATH.
	for nvm_sh in \
	"$HOME/.nvm/nvm.sh" \
	/opt/homebrew/opt/nvm/nvm.sh \
	/usr/local/opt/nvm/nvm.sh \
	"$(brew --prefix nvm 2>/dev/null)/nvm.sh"; do
	if [ -s "$nvm_sh" ]; then
	. "$nvm_sh" --no-use
	nvm use >/dev/null 2>&1 || nvm use default >/dev/null 2>&1
	break
	fi
	done

with this PR too?

[olerass]

LGTM! Small question, do we want then to remove this logic

rainbow/ios/.xcode.env

Lines 34 to 46 in baf3acb

	# 2) nvm -- source it and honor .nvmrc when present. Probe absolute Homebrew
	# paths too, since `brew` itself may not be on Xcode's stripped PATH.
	for nvm_sh in \
	"$HOME/.nvm/nvm.sh" \
	/opt/homebrew/opt/nvm/nvm.sh \
	/usr/local/opt/nvm/nvm.sh \
	"$(brew --prefix nvm 2>/dev/null)/nvm.sh"; do
	if [ -s "$nvm_sh" ]; then
	. "$nvm_sh" --no-use
	nvm use >/dev/null 2>&1 || nvm use default >/dev/null 2>&1
	break
	fi
	done

with this PR too?

Oh yes! Good catch. I completely forgot I added this last month 🤦 Will push fix

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Launch in simulator or device for 8da5ef6