Use Npgsql 8.0.0-preview.1

[roji]

Starting out with monthly updates for 8.0.

Also did a bit of general version bumps.

For completeness, here are the two runs, before and after:

db	before	8.0.0-preview
CPU Usage (%)	35	34	-2.86%
Cores usage (%)	972	961	-1.13%
Working Set (MB)	46	45	-2.17%
Build Time (ms)	1,460	1,447	-0.89%
Start Time (ms)	436	429	-1.61%
Published Size (KB)	523,834	523,834	0.00%

application	before	8.0.0-preview
CPU Usage (%)	97	96	-1.03%
Cores usage (%)	2,711	2,690	-0.77%
Working Set (MB)	564	571	+1.24%
Private Memory (MB)	1,313	1,319	+0.46%
Build Time (ms)	2,965	2,953	-0.40%
Start Time (ms)	1,693	1,820	+7.50%
Published Size (KB)	96,349	96,438	+0.09%
Symbols Size (KB)	45	45	0.00%
.NET Core SDK Version	8.0.100-preview.3.23156.1	8.0.100-preview.3.23156.1

load	before	8.0.0-preview
CPU Usage (%)	39	39	0.00%
Cores usage (%)	1,103	1,099	-0.36%
Working Set (MB)	48	48	0.00%
Private Memory (MB)	363	363	0.00%
Start Time (ms)	0	0
First Request (ms)	108	108	0.00%
Requests/sec	474,946	475,633	+0.14%
Requests	7,171,775	7,181,739	+0.14%
Mean latency (ms)	1.22	1.13	-7.38%
Max latency (ms)	49.73	22.23	-55.30%
Bad responses	0	0
Socket errors	0	0
Read throughput (MB/s)	616.46	617.35	+0.14%
Latency 50th (ms)	1.01	1.01	0.00%
Latency 75th (ms)	1.22	1.21	-0.82%
Latency 90th (ms)	1.55	1.50	-3.23%
Latency 99th (ms)	5.39	3.94	-26.90%