ci: give the runner 6 GB, since the analysis needs 5.4 GB cold

With Todo and the shared packages in the workspace, a cold `dart analyze`
peaks at about 5.4 GB (3.7 GB warm). Above the 4 GB soft limit the
kernel slowed it to a crawl, and at 5 GB it killed the job. Analysing
parts from the root drops the lint plugin's rules, so the limit rises
instead, and the kernel kills CI first should the server run out.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Signed-off-by: Tizian 「ティツィアーン」 <raisondetredev@pm.me>

deploy/runner/forgejo-runner.service

@@ -66,13 +66,16 @@ SystemCallFilter=~@clock @cpu-emulation @debug @module @mount @obsolete @raw-io
 SystemCallErrorNumber=EPERM
 UMask=0077
 
-# Never at the instance's expense: two of the four cores, at most 5 GB of the 8 (the
-# kernel reclaims from CI first above 4 GB), and the lowest priority for CPU and disk.
-# A cold `dart analyze` of the workspace with its lint plugin needs about 3.7 GB; with
-# 3 GB the kernel killed it, and OOMPolicy's default then stopped the whole unit.
+# Never at the instance's expense: two of the four cores, at most 6 GB of the 8 (the
+# kernel reclaims from CI first above 5.5 GB), the lowest priority for CPU and disk, and
+# CI's processes the first the kernel kills should the whole server run out of memory.
+# A cold `dart analyze` of the workspace with its lint plugin needs about 5.4 GB since
+# Todo and the shared packages joined it (3.7 GB warm); below that the kernel slowed it
+# to a crawl and then killed it, and OOMPolicy's default then stopped the whole unit.
 CPUQuota=200%
-MemoryHigh=4G
-MemoryMax=5G
+MemoryHigh=5.5G
+MemoryMax=6G
+OOMScoreAdjust=1000
 TasksMax=2048
 Nice=10
 IOSchedulingClass=best-effort